Coolflex Essentials Pocket King Size Mattress
The Coolflex Essentials Pocket Mattress is an entry-level hybrid, pairing an 800 pocket spring unit with a soft Reflex foam comfort layer under a knitted cover.
- Minimises partner disturbance
- Support that adjusts to your shape
- Cushions shoulders & hips
£229
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Coolflex Essentials Pocket Mattress
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Mattress details
Mattress
Coolflex Essentials Pocket Mattress
Size
Firmness
Medium Firm
Construction
Foam
Pocket Spring
Hybrid
Depth (cm)
24
Layers
3
Layer Details
Knitted cover
A super-soft knitted cover with a touch of breathability, which means a gentler first impression when you lie down and a little help letting warm air escape.
Soft foam comfort layer
A layer of soft Reflex foam sits beneath the cover, cushioning shoulders and hips. It softens the feel of the springs below without making the mattress feel plush overall.
800 pocket spring unit
Pressure-reactive springs work independently, which means support tailored to where your body needs it and virtually no motion transfer across the bed. If you share, you should feel far less of your partner's movement.
Layer details from mattressnextday.co.uk product page, September 2026.
Key benefits
- Space that suits the springs: With 75cm each for two people sharing, the independently moving pocket springs have room to do their job, supporting each of you separately rather than as one unit.
- Less disturbance on different schedules: If one of you gets up hours before the other, the pocket spring unit at this width keeps that early exit from travelling across the bed.
- Length for taller sleepers: At 200cm long, the UK king is 10cm longer than the UK double, a genuine relief for anyone whose feet reach the end of a standard-length bed.
- A budget-friendly step up: Upgrading to a UK king usually means a bigger spend, so an entry-level hybrid makes the move to more space easier to justify.
- Easy to dress: Standard king sheets and a 230 x 220cm king duvet fit, and the 24cm depth means ordinary fitted sheets go on without a struggle.
This size suits you if...
You share the bed every night and a double has started to feel cramped, one of you rises early or comes to bed late and you'd rather not feel it, or someone in the bed is nudging six foot and needs the extra 10cm of length a UK king provides over a UK double.
Consider another size if...
Your bedroom is smaller than the 2.7m x 2.9m we suggest for a UK king, or you sleep alone. In either case we'd recommend the UK double instead, which needs at least 2.6m x 2.8m.
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FAQ's
Is the Coolflex Essentials in a UK king good for couples?
It's a sensible fit. The 800 pocket springs work independently, so at 75cm each for two people sharing, one partner shifting or getting up early transfers very little movement to the other. The medium firm feel suits most sleeping positions, although anyone wanting a properly firm surface should look at a different model rather than a different size.
Will the UK king Coolflex Essentials suit a tall sleeper?
The length is the quiet win here. At 200cm, the UK king is 10cm longer than the UK double, which matters if either of you is approaching six foot and used to sleeping diagonally to fit. Just check your bed frame takes a 150 x 200cm mattress, since some older king frames were sized differently.
What room size do I need for a Coolflex Essentials UK king?
We suggest at least 2.7m x 2.9m, with more feeling comfortable once wardrobes and bedside tables are in. New build master bedrooms can be tighter than they first appear, so measure with furniture in place. If the room falls short, the UK double needs at least 2.6m x 2.8m and still sleeps two.
Is it worth going up to the UK super king instead of the king?
The UK super king is 30cm wider than the UK king, the same length, and we suggest at least 3m x 2.9m of room for it. If a dog routinely claims part of the bed, or you simply want maximum spread, the extra width helps. For most couples upgrading from a double, the UK king is the more practical jump.
How heavy is the Coolflex Essentials king to move?
Coolflex doesn't publish a weight for this mattress. It arrives vacuum-sealed, which makes getting it upstairs far easier than a full-size mattress would be, and it expands within 24 hours of unpacking. Once expanded, a 150 x 200cm hybrid is a two-person job to rotate, which you'll do periodically since it's single-sided.