Jay-Be Flex Ultra Firm E-Pocket 1200 Small Double Mattress in a Box
The Jay-Be Flex Ultra Firm E-Pocket 1200 is a boxed mattress built for people who want genuinely firm support, not the medium-firm feel most brands settle on.
- Ultra-firm for back & front sleepers
- Foam-free with recycled fibres
- 10-year guarantee
£363.72
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Jay-Be Flex Ultra Firm E-Pocket 1200 Mattress in a Box
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Mattress details
Mattress
Jay-Be Flex Ultra Firm E-Pocket 1200 Mattress in a Box
Size
Firmness
Extra Firm
Construction
Foam
Pocket Spring
Rolled
Eco-Friendly
Depth (cm)
21
Layers
3
Layer Details
Advance e-Fibre™
A deep-quilted top layer of Advanced e-Fibre, which gives the sleep surface a softer first impression than the name ultra-firm might suggest. It also wicks moisture, which means better temperature regulation through the night.
Firm e-Fibre™
A densely packed comfort layer that delivers a firm feel with some pressure relief. This is where the mattress earns its firmness rating, sitting between you and the springs.
Ultra-Firm Sprung Core
The support layer, engineered for stability that lasts. It keeps the mattress from softening into a dip over time, which means consistent support night after night.
Layer details from jaybe.com product page, September 2026.
Key benefits
- Real space for one firm sleeper: At 120cm wide, it's 30cm wider than a UK single, so a solo back or front sleeper can shift position without reaching the edge.
- Fits rooms a double overwhelms: The UK small double is 15cm narrower than a UK double, which can be the difference between a door that clears the bed and one that doesn't.
- A modest footprint needs a modest room: We suggest allowing at least 2.4m x 2.8m, comfortably within reach of box rooms, studio flats and loft conversions.
- Slim profile suits smaller spaces: The 21cm depth keeps the bed low and unimposing, which helps in a loft room where headroom beside the bed is already tight.
- A sensible guest room choice: Occasional couples can share a UK small double for a night or two, and the ultra-firm feel holds its shape rather than rolling both sleepers together.
This size suits you if...
You sleep alone, find most mattresses too soft, and have outgrown the width of a single without having the floor space for a full double. It also fits if you're furnishing a guest room or holiday let where couples stay occasionally rather than nightly, or a teenager's room where a single feels cramped but every centimetre of floor still matters.
Consider another size if...
You share the bed with a partner every night, because 120cm is tight for two adults long term. We'd recommend the UK double instead, and we suggest allowing at least 2.6m x 2.8m of room for it.
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FAQ's
What are the dimensions of the Jay-Be Flex Ultra Firm in a UK small double?
The UK small double measures 120 x 190cm, which is 4ft x 6ft 3in. That's 30cm wider than a UK single and the same length, so it adds sideways room without eating further into the room. Standard 4ft fitted sheets fit it, and most people pair it with a regular double duvet.
Will the small double Jay-Be Flex Ultra Firm fit in a box room?
Usually, yes. We suggest allowing at least 2.4m x 2.8m so you can still open the door and walk around one side of the bed. Measure the room including alcoves and radiators before ordering. The mattress arrives rolled in a box, which makes getting it up a narrow staircase far easier than carrying a flat mattress.
Can two people sleep on the UK small double Jay-Be Flex Ultra Firm?
For occasional nights, yes, which makes it a reasonable guest room pick. At 120cm wide it's snug for two adults, so we wouldn't suggest it for couples sharing every night. The ultra-firm build does help here: the surface stays stable at the edges, so neither sleeper drifts into the middle.
Is a small double big enough for one adult who likes a firm mattress?
Yes, and for many solo sleepers it's the sweet spot. The extra 30cm over a UK single gives you room to stretch and change position, which matters on a firm surface where you tend to sleep on top of the mattress rather than settling into one spot.
Where can I check prices for this mattress in a small double?
Compare the retailers listed on this page. The prices shown here are updated as retailers change them, so it's the quickest way to see what the UK small double currently costs and who has it in stock, rather than checking each retailer's site in turn.