Sealy Advantage Sapphire Geltex Pillow Top Small Double Mattress
The Sealy Advantage Sapphire Geltex Pillow Top Mattress combines a plush pillow top with a gel-infused Geltex comfort layer, which means a cushioned surface that eases pressure where you feel it most.
- Eases pressure where you feel it
- Support that responds as you move
- Reinforced edges for steady sides
£599
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Sealy Advantage Sapphire Geltex Pillow Top Mattress
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Mattress details
Mattress
Sealy Advantage Sapphire Geltex Pillow Top Mattress
Size
Firmness
Medium
Construction
Gel
Memory Foam
Pocket Spring
Depth (cm)
28
Layers
3
Layer Details
Pillowtop
A plush pillow top that adds an extra layer of cushioning, which means a softer-feeling surface than the medium rating alone suggests.
Geltex comfort layer
A cushioned, gel-infused Geltex layer that relieves pressure on the parts of the body that feel it most, so your hips and shoulders get some extra give.
PostureTech CS spring system
Pocket springs that respond to shifts in body weight to give localised support, with Edge Guard foam strips inside the spring unit. You get support that follows your movements, plus steadier edges.
Layer details from mattressnextday.co.uk product page, October 2026.
Key benefits
- Room to spread out alone: The UK small double is 30cm wider than the UK single, which means a solo sleeper can turn over, stretch an arm out or curl up without hitting the edge.
- Fits rooms a double would crowd: Being 15cm narrower than the UK double, it can leave you a usable walkway or a bedside table in a box room that would otherwise feel wall to wall.
- Steadier sides on a narrower bed: Sealy fits Edge Guard foam strips inside the spring unit, which matters on a smaller mattress because you're more likely to sleep close to the edge.
- Cushioning for one body shape: The pillow top and Geltex layer give hips and shoulders some extra give, and sleeping alone means the PostureTech CS springs respond to your weight only.
- Easy bedding and frames: The 4ft width is a standard UK size, so frames and sheets are simple to find, although fitted sheets need enough pocket depth for a 28cm mattress.
This size suits you if...
You sleep alone and feel hemmed in on a single, your teenager has outgrown their single but the bedroom can't spare much floor, or you're kitting out a guest room where couples stay for the odd weekend rather than every night.
Consider another size if...
You share the bed every night with a partner. We'd recommend the UK double instead, which gives 67.5cm each for two sharing; we suggest at least 2.6m x 2.8m for the UK double.
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FAQ's
Is the Sealy Advantage Sapphire Geltex Pillow Top UK small double big enough for two people?
For a night or a weekend, yes, most couples manage. For nightly sharing it's a squeeze, as the UK small double is 15cm narrower than the UK double. If you share every night, the UK double gives 67.5cm each and we suggest a room of at least 2.6m x 2.8m for it.
What size bedroom do I need for a UK small double mattress?
We suggest allowing at least 2.4m x 2.8m for a UK small double. That leaves space to get in and out comfortably and open the door. If your room is tighter than that, measure where the door swings and where any wardrobe sits before you commit.
Is a UK small double a good next bed for a teenager outgrowing a single?
It often is. The UK small double is 30cm wider than the UK single but the same length, so it adds sideways room without eating into floor space at the foot of the bed. The medium rating with a pillow top suits a growing teenager who wants some cushioning.
Will a UK small double fit in a loft conversion bedroom?
Often, yes, which is why many people choose it for attic rooms. A sloping ceiling can leave little standing room beside a wider bed, and the UK small double's 120cm width gives you more clearance on at least one side. Measure the full-height floor area, not the whole room.
What sheets and duvet fit a UK small double Sealy Sapphire Geltex?
Look for fitted sheets labelled small double or 4ft, with pockets deep enough for a 28cm mattress, as the pillow top adds height. A standard double duvet works well on a UK small double and gives a little overhang on each side.