Sleepeezee ActivFlex Response 3600 Pocket Pillow Top King Size Mattress
The Sleepeezee ActivFlex Response 3600 Pocket Pillow Top Mattress combines two Staycool Gel foam layers with three tiers of pocket springs, which means a soft, cushioned surface that stays cool with support underneath.
- Cushioned pillow top comfort
- Gel layers keep you cooler
- 10-year guarantee
£1,299
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Sleepeezee ActivFlex Response 3600 Pocket Pillow Top Mattress
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Mattress details
Mattress
Sleepeezee ActivFlex Response 3600 Pocket Pillow Top Mattress
Size
Firmness
Medium Soft
Construction
Foam
Gel
Pocket Spring
Depth (cm)
33
Layers
9
Layer Details
Soft knitted cover
The knitted pillow top cover that you sleep on. It gives the mattress a soft, quilted-feel finish.
Soft polyester comfort layer
A soft polyester fibre layer under the cover. It adds surface cushioning, so the mattress feels gentle as you lie down.
Staycool Gel
Two dedicated layers of Staycool Gel foam, which Sleepeezee describes as pressure-sensitive and cooling. They ease pressure and help the surface stay cooler.
ActivFlex spring foam
A profiled foam that combines the adaptive benefits of foam with the responsiveness of springs. You get contouring without feeling stuck in the mattress.
1000 mini comfort springs
A top layer of mini pocket springs nestled within the pillow top. They add a responsive, close-fitting layer of comfort near the surface.
1400 mini comfort springs
A middle layer of mini pocket springs that adds responsiveness. It helps the mattress react as you move.
1200 traditional pocketed springs
The core layer of main pocket springs that provides the foundation and support. This is what holds your weight steady beneath the softer layers.
Fully encapsulated spring unit
A high-density foam border surrounds the spring unit to give edge-to-edge support. It makes the sides firmer to sit on and gives you more usable sleeping space.
Foundation support pad
A support pad that forms the foundation for the layers above. It sits at the base and supports the springs.
Layer details from sleepeezee.com product page, October 2026.
Key benefits
- More room each: You get 75cm each for two sharing, which means elbows and knees are less likely to meet in the night than on a UK double.
- Length for taller sleepers: At 200cm long, the UK king is 10cm longer than a UK double, so a partner over six foot is less likely to have feet hanging off the end.
- Less disturbance from early risers: Pocket springs move individually, and the extra width puts a little more distance between you, so one of you getting up at dawn should disturb the other less.
- Steadier sides for getting up: The high-density foam border around the springs makes the edges firmer to sit on, which helps if you're recovering from surgery or getting out of bed carefully.
- Space to shift and prop: Through pregnancy and the months after, the extra width leaves room for propping pillows without pushing your partner towards the edge.
This size suits you if...
You share the bed every night and keep bumping into each other on a UK double, or one of you is tall enough that 190cm feels short. It also fits if you like a medium soft, cushioned surface and your partner's movements tend to wake you.
Consider another size if...
Your bedroom is under our suggested minimum of 2.7m x 2.9m once wardrobes are in. We'd recommend the UK double instead, which needs at least 2.6m x 2.8m.
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FAQ's
Is the Sleepeezee ActivFlex Response 3600 pillow top king big enough for two adults?
For most couples, yes. The UK king gives 75cm each for two sharing, compared with 67.5cm each on a UK double. If a dog sleeps on the bed every night, though, that space can shrink quickly. The UK super king gives 90cm each.
What size room do I need for a UK king pillow top mattress?
We suggest at least 2.7m x 2.9m, and 3.2m x 3.2m is more comfortable if you want space to walk round both sides. New build master bedrooms can feel tighter than their floor plan once fitted wardrobes are in, so measure from the wardrobe doors rather than the walls.
Is a UK king long enough for someone over 6ft?
The UK king is 200cm long, which is 10cm longer than a UK double, UK small double or UK single. For a partner approaching or over six foot, that extra length is often a bigger reason to choose a UK king than the width.
Should we get the UK king or the UK super king in the Sleepeezee ActivFlex Response 3600?
The UK super king is 30cm wider but the same length, giving 90cm each instead of 75cm. If you're on very different schedules and want the most distance between you, the UK super king would suit you better, although we suggest at least 3m x 2.9m for it.
Will the Sleepeezee ActivFlex Response 3600 king fit a standard king bed frame and sheets?
It measures 150 x 200cm, so it fits a UK king frame, and a 230 x 220cm king duvet fits. At 33cm deep, check that your fitted sheets have pockets deep enough to grip the corners, and that the frame won't leave the top of the mattress sitting awkwardly high.