Sealy Advantage Sapphire Geltex Pillow Top Super King 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
£869
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Sealy Advantage Sapphire Geltex Pillow Top Mattress
More available sizes
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
- Distance from a restless partner: You each get 90cm, which means a partner who turns over all night is further away from you than any comfort layer could manage on a smaller bed.
- Room when the family piles in: The UK super king is 30cm wider than the UK king, so a child arriving at 3am or a large dog stretching out doesn't push an adult to the edge.
- Sides you can sleep on: Edge Guard foam strips sit inside the spring unit, which helps when a crowded bed means someone ends up lying close to the side.
- Cushioning wherever you end up: The pillow top and Geltex layer run across the full 6ft width, so whoever gets squeezed into the middle still has some give at the hips and shoulders.
- In proportion with a large room: In a period property or a generous master bedroom, a UK king can look a little lost, while a 6ft x 6ft 6in bed fills the space more naturally.
This size suits you if...
You share with a partner who tosses and turns, children or a large dog end up in the bed most nights, and your bedroom comfortably clears our suggested minimum of 3m x 2.9m.
Consider another size if...
Your bedroom is tighter than 3m x 2.9m, or a bed this wide would struggle round your landing. We'd recommend the UK king instead, which needs at least 2.7m x 2.9m.
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FAQ's
What size bedroom do I need for a UK super king Sealy Advantage Sapphire?
We suggest at least 3m x 2.9m, and around 3.5m x 3.2m feels more comfortable once bedside tables are in. Check the wardrobe and door swing too. In a loft conversion, the slope of the roof usually decides which wall the headboard can go against, so measure the full-height section first.
Is a UK super king big enough for two adults and a child?
It's the most realistic option for it. Two adults get 90cm each, and the extra 30cm over the UK king is often what lets a small child settle between you without someone clinging to the edge. If it happens most nights rather than occasionally, the UK super king is the size we'd choose.
How much more space does a UK super king give than a UK king?
The UK super king is 30cm wider than the UK king and the same length. For two people sharing, that works out at 90cm each instead of 75cm each, so 15cm more per person. With a restless partner, that extra gap is often noticeable.
Will a super king pillow top mattress fit up my stairs?
Measure before you order. This mattress is 180cm wide and 28cm deep, and a pillow top doesn't bend round corners as easily as a thinner mattress. Check tight landing turns, the stairwell ceiling and the bedroom door frame, then compare the retailers listed on this page.
What bedding fits a UK super king Sealy Advantage Sapphire Geltex?
You'll need super king sheets and a 260 x 220cm duvet. Choose deep fitted sheets so they reach over the pillow top on a 28cm mattress. Super king bedding costs more than standard sizes, and there's usually less choice in the shops, so factor that in.