Bed fitting guide
Pull Out Bed Mechanism — Eolo, Alby-M and Boxy Compared
How pull-out and trundle bed fittings work, what the numbers mean and how to plan the cabinet around them.
The short answer
A pull-out bed mechanism rolls a second bed out from under a main bed or sofa. Mirano's range covers three approaches: Eolo, a semi-automatic gas-spring trundle that closes to 85mm; Alby-M, an automatic head-pull fitting that closes to 12cm; and Boxy, a convertible sofa and bed that pairs into a double. Check the internal box size, mattress weight and open-room clearance before you choose.
A second bed that disappears is one of the most useful tricks in a small home. The same mechanism that makes it work, though, is also what makes it a poor buy if the cabinet is the wrong size, the mattress is too heavy or the closed height does not fit under the main bed.
This guide explains how pull-out bed mechanisms work, compares Mirano's Eolo, Alby-M and Boxy fittings on the numbers, and gives a checklist for planning the cabinet around them. All product figures come from Mirano's published bed fitting specifications. Where we add general guidance, we say so.
The basics
What is a pull-out bed mechanism?
A pull-out bed mechanism lets a second bed roll out from underneath a main bed, a sofa or a platform, and slide back in when it is not needed. It is often called a trundle bed fitting. The fitting supplies the frame, the wheels or runners and the lifting or spring action that brings the bed up to usable height.
It is a different tool from a storage bed, which lifts a mattress base to reach storage, and from a wall bed, which folds a full bed vertically into a cabinet. If you are still choosing between those, our guides to hydraulic bed fittings and wall bed prices cover the other two.
| Bed type | What it does | Best when |
|---|---|---|
| Pull-out (trundle) bed | Hides a second bed under the main bed | Occasional guests, kids' shared rooms, multi-purpose rooms |
| Storage bed (hydraulic or gas spring) | Lifts the mattress base to reach storage underneath | You need linen and luggage storage more than a second bed |
| Wall bed | Folds a full bed vertically into a cabinet | The room doubles as a living, work or guest space |
How they work
Three ways a pull-out bed can open
Mirano's pull-out range shows the three common approaches.
- Automatic head-pull (Alby-M): The bed opens with a head-pull action and rolls out on no-trace wheels. A curved metal profile on the slatted top adds comfort without extra padding underneath.
- Semi-automatic gas spring (Eolo): A push-pull system backed by calibrated gas springs makes extending and retracting the bed smooth with little effort, so the frame never has to be lifted or dragged by hand.
- Convertible daybed or sofa (Boxy): The unit works as a single bed or a daytime sofa. Pair two units and they form one solid double bed top on non-marking wheels, with a fabric grip handle for operation.
Side by side
Eolo vs Alby-M vs Boxy: the numbers
| Specification | Eolo | Alby-M | Boxy |
|---|---|---|---|
| Opening action | Semi-automatic, gas spring push-pull | Automatic, head-pull | Pull open using a fabric grip handle |
| Bed size | 800 × 1880mm | Unit size 800 × 1900mm | Upper bed 900 × 2020mm; lower bed 800 × 1900mm |
| Closed height | 85mm (closed bed frame) | 12cm | 340mm (unit height) |
| Open height | 330mm (open bed frame) | 35cm | Not listed separately |
| Mattress weight | 10 to 15kg | 15kg | Maximum mattress height 150mm |
| Internal box | Minimum 850 × 1920 × 280mm | Cabinet internal 900 × 1950mm; bedspring height 320 to 350mm | Closed depth 956mm; open depth 1785mm; width 2070mm |
| Floor protection | Not listed | No-trace wheels | Non-marking wheels |
| Best suited for | Kids' shared rooms, guest rooms | Guest bedrooms, children's rooms, a hidden second bed under a main bed | Living rooms, studios, modular seating that converts to sleeping |
Source for every figure above: Mirano's published bed fitting specifications. Total structure dimensions can vary slightly with the height of the feet used.
Alby-M
Alby-M: automatic pull-out with head pull
Alby-M is an automatic pull-out bed fitting with a head-pull opening action, available in single or headboard models. It rolls on no-trace wheels that protect flooring, and its front panel brackets give a clean, finished look once installed.
The standout numbers are the height range: it opens to 35cm and closes to just 12cm, so it fits under most standard bed frames. The unit size is 800 × 1900mm, with a bedspring height of 320 to 350mm and a cabinet internal size of 900 × 1950mm, designed for a 15kg mattress. Mirano lists compatible mattress sizes of 75 × 185cm, 80 × 185cm and 80 × 190cm for singles with a 40 × 30 profile, and 160 × 190cm and 160 × 200cm for doubles with a 60 × 30 profile; confirm the combination for your model.
Choose it when: you want the second bed to open with one confident pull, the clearance under the main bed is limited, and the sleeper is a guest or a child rather than someone using it nightly.
Watch out for: the cabinet internal size and the mattress weight. A heavier mattress than the 15kg rating is the quickest way to strain the mechanism.
Eolo
Eolo: semi-automatic gas spring trundle
Eolo is a steady, sturdy trundle fitting with semi-automatic, spring-assisted opening. Calibrated gas springs make extending and retracting the bed smooth with minimal effort. It includes a 4-piece U-bolt kit for securing the front panel.
Its closed bed frame height is only 85mm, rising to 330mm when open, which makes it the lowest-profile option in this range. It is specified for mattresses of 10 to 15kg and a bed size of 800 × 1880mm. The minimum internal box size is 850 × 1920 × 280mm, so the base cabinet or bed box has to be built with that clearance.
Choose it when: the main bed is low and you need the trundle to disappear, for example in a children's shared room.
Watch out for: the 280mm minimum internal height. Feet height changes the overall dimensions, so settle the foot height before you finalise cabinet drawings.
Boxy
Boxy: convertible sofa and pull-out bed
Boxy is a flexible pull-out fitting that works equally well as a single bed or a daytime sofa. Two units can be paired into one solid double bed, which gives a furniture designer a single hardware system for both a standalone daybed and a full double configuration. It runs on non-marking wheels and has a practical fabric grip handle.
The published figures are a unit height of 340mm, a width of 2070mm, a closed depth of 956mm and an open depth of 1785mm. The upper bed frame takes a 900 × 2020mm mattress and the lower bed frame an 800 × 1900mm mattress, and the maximum mattress height is 150mm.
Choose it when: a living room or studio has to serve as a seating area by day and a bedroom for guests at night.
Watch out for: the open depth of 1785mm. Measure the room with the bed fully extended, not just closed.
Planning
How to plan the space and the cabinet
General planning guidance, applied to the figures above.
- Measure open and closed: Check the room with the bed extended. Boxy, for example, needs 1785mm of depth when open against 956mm when closed.
- Fix the foot height first: Mirano notes that total structure dimensions vary with foot height. A few millimetres decide whether the front panel clears the floor.
- Match mattress weight to the rating: Eolo and Alby-M are rated for 10 to 15kg mattresses. A heavy spring mattress does not belong on them.
- Check the floor: Wheels protect flooring only on a clean, firm surface. Thick pile carpet adds drag; plan the rolling path accordingly.
- Plan the front panel: Alby-M uses brackets and Eolo a 4-piece U-bolt kit. Allow for the fixing in the carpentry drawings.
- Leave a clear zone: Allow floor space beside the open bed for getting in and out. This is general ergonomic advice, not a Mirano specification.
Alternatives
Pull-out bed, sofa bed or folding guest bed?
A pull-out bed is not the only way to give a room a second sleeping surface. The best choice depends on how the room is used by day.
| Option | Strength | Limitation |
|---|---|---|
| Pull-out (trundle) bed | The second bed disappears completely under the main bed | Needs a main bed with enough clearance; mattress weight is limited |
| Convertible sofa and pull-out (Boxy) | The room keeps a sofa by day | Needs floor space to open, 1785mm of depth for Boxy |
| Wall bed | Frees the whole floor by day | Needs a dedicated cabinet and wall; see our wall bed guide |
| Loose folding bed | Cheapest and most portable | Has to be stored somewhere and set up each time |
If the room is a primary bedroom, a trundle will rarely be the answer. If it is a children's room that needs a sleepover bed, or a guest room used a few nights a month, a pull-out bed is usually the most practical and the cleanest looking.
Worked example
A worked example: a children's shared room
A client wants two children to share a room, with a spare bed for sleepovers. The main bed is 800mm wide and 1,900mm long. The trundle should disappear entirely when not in use.
Eolo is the natural fit. It takes an 800 × 1880mm bed and a mattress of 10 to 15kg, which suits a light foam mattress for a child, and it closes to only 85mm in frame height. The designer builds the bed base with an internal box of at least 850 × 1920 × 280mm, fixes the front panel with the supplied U-bolt kit and confirms the foot height before issuing drawings.
If the client prefers a one-handed automatic action for an adult guest room, Alby-M, which opens by a head pull and closes to 12cm, is the better match. If the room doubles as a lounge, Boxy changes the answer again. The same room can lead to three different specifications, which is why the use case comes first.
Safety
Safety and usability notes
General guidance for family rooms, not a Mirano specification: keep fingers clear when the bed extends or retracts, avoid leaving heavy items on the extended frame, and do not let children play on the mechanism. Check the load rating for adult use, and replace any fitting that starts to bind or sag rather than forcing it. Review the manufacturer's installation instructions with your carpenter before the front panel is fixed.
Common mistakes
Mistakes to avoid
- Treating it as the main bed: These fittings are designed for occasional use. For nightly use choose a full frame or a wall bed.
- Ignoring the internal box size: The cabinet or bed box must meet the minimum internal dimensions, including height.
- Overlooking mattress weight: Rated mattress weight is part of the specification, not a suggestion.
- Forgetting open-room clearance: A bed that fits when closed can block a door or wardrobe when open.
- Mixing up bed types: A trundle, a storage bed and a wall bed solve different problems. Choose by use first.
Decision framework
Which fitting should you specify?
| If you need | Choose | Why |
|---|---|---|
| A hidden second bed under a low main bed | Eolo | 85mm closed frame height and gas-spring assistance |
| Effortless automatic opening for guests or children | Alby-M | Automatic head-pull, closes to 12cm |
| A sofa by day and a bed by night, possibly a double | Boxy | Converts, and two units pair into one double top |
| Many identical bed frames across a hospitality project | Hotel Bed Fitting | Self-supporting frame, see our hotel furniture hardware guide |
For project quantities, our team can review cabinet drawings and mattress specifications before production. Share the room layout, mattress sizes and quantity through the quote form, and see the full bed fittings range.
Clear answers
Frequently asked questions
What is a pull-out bed mechanism?
A pull-out bed mechanism is a fitting that lets a second bed roll out from under a main bed or sofa and tuck away again when it is not needed. It is also called a trundle bed fitting. The mechanism handles the rolling, the lifting of the bed frame to mattress height and, in some versions, the gas-spring or automatic opening.
What is the difference between Eolo, Alby-M and Boxy?
Eolo is a semi-automatic trundle with calibrated gas springs and a very low closed height of 85mm. Alby-M is an automatic pull-out with a head-pull opening action that closes to 12cm and opens to 35cm. Boxy is a convertible system that works as a single bed or a daytime sofa and pairs with a second unit to form a double bed.
How much space do I need under the main bed for a pull-out bed?
It depends on the fitting. For Eolo, Mirano lists a minimum internal box size of 850 × 1920 × 280mm. For Alby-M, the cabinet internal size is 900 × 1950mm with a closed height of 12cm. Always check the specific fitting and allow for the height of the feet, because total structure dimensions vary with it.
What mattress weight can a pull-out bed carry?
Eolo is listed for mattresses of 10 to 15kg and Alby-M for a 15kg mattress. These are light foam or similar mattresses, so a standard heavy spring mattress is not suitable. Always check the mattress weight against the fitting before ordering.
Is a pull-out bed suitable for daily use?
Pull-out beds are designed mainly for occasional guests, children's shared rooms and multi-purpose rooms. For a bed that will be used every night, a full bed frame or a wall bed designed for daily use is usually the better choice.
Will a pull-out bed scratch my floor?
Alby-M runs on no-trace wheels and Boxy on non-marking wheels, both designed to protect flooring from scuff marks. Even so, check the floor finish and keep the rolling path clear of grit.
Can I pair two Boxy units to make a double bed?
Yes. Mirano describes the Boxy system as pairing with a second unit so the two combine into one solid, indivisible sleeping surface, which gives designers a single system for a daybed and a double-bed configuration.
What is the difference between a pull-out bed, a storage bed and a wall bed?
A pull-out bed hides a second bed under a main bed. A storage bed lifts the mattress base to reach storage underneath. A wall bed folds a full bed vertically into a cabinet. Each solves a different space problem, so pick by how often the bed is used and how much floor space you have.
Can pull-out bed fittings be used in hotels or service apartments?
They are best for guest and family rooms. For hospitality projects that need many identical bed frames, a self-supporting frame such as Mirano's Hotel Bed Fitting is a more suitable choice.
Do pull-out bed fittings come with a front panel fixing?
Alby-M includes brackets for clean front-panel fastening and Eolo includes a 4-piece U-bolt kit for securing the front panel. Confirm the front panel fixing for the fitting you specify.
Specify with confidence
Specify pull-out bed fittings with confidence
Share your room layout and mattress sizes, and our team will match the fitting and review the cabinet clearances.