Komfi Serenity Pocket 1000 King Size Mattress in a Box
The Komfi Serenity Pocket 1000 Mattress in a Box combines individually sleeved pocket springs with a soft reflex foam top, which means a medium feel with less partner disturbance, delivered rolled up.
- Medium support for most sleepers
- Minimises partner disturbance
- Removable cover washes in the machine
£308.03
Get the lowest price we've found
Save with the previous model
Some retailers still sell the earlier version of this mattress for less than the current model's best price.
Komfi Serenity Pocket 1000 Mattress in a Box
More available sizes
Mattress details
Mattress
Komfi Serenity Pocket 1000 Mattress in a Box
Size
Firmness
Medium
Construction
Foam
Pocket Spring
Rolled
Depth (cm)
20
Layers
2
Layer Details
Reflex foam
A soft, high density reflex foam that's hypo-allergenic. It gives a little cushioning on top of the springs, so the medium feel is softened at the surface.
Pocket spring core
Small diameter pocket springs, each housed in its own cloth sleeve. Because they move independently, they minimise partner disturbance and support you where you lie.
Layer details from archerssleepcentre.co.uk product page, October 2026.
Key benefits
- More room for each of you: At 75cm each for two sharing, you get 7.5cm more personal space than on the UK double, which means fewer elbows when one of you turns over.
- Length for taller partners: The UK king is 200cm long, 10cm longer than the UK double, so a partner nearing six foot can stretch out without their feet reaching the edge.
- Calmer early starts: If one of you gets up hours before the other, the independent pocket springs should keep that movement on their side, helped by the extra width between you.
- Space for a pregnancy pillow: The wider surface leaves room for a support pillow without pushing your partner to the edge, and the medium feel should suit side sleepers of average build.
- Easier to get upstairs: It arrives rolled and vacuum packed, so a 5ft x 6ft 6in mattress is easier to carry up a narrow staircase than a flat one would be.
This size suits you if...
You share the bed every night and keep bumping into each other on a UK double, one of you is close to six foot and runs out of length, or your partner gets up much earlier and you'd like more distance between you.
Consider another size if...
Your bedroom is smaller than our suggested 2.7m x 2.9m for a UK king. We'd recommend the UK double instead, for which we suggest at least 2.6m x 2.8m.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
FAQ's
What room size do I need for a Komfi Serenity Pocket 1000 UK king?
We suggest at least 2.7m x 2.9m for the UK king, which measures 150 x 200cm. New build master bedrooms can feel smaller once fitted wardrobes go in, so measure from the wardrobe doors rather than the walls, and leave room to walk round both sides.
How much space does each person get on a UK king?
Sharing a UK king gives you 75cm each. The UK double gives 67.5cm each, so you gain 7.5cm apiece. It sounds modest, but on a pocket spring mattress designed to limit motion, a little extra distance helps when one of you is restless.
Is a UK king long enough for someone over 6ft?
The UK king is 200cm long, or 6ft 6in, which is 10cm longer than the UK double. If one of you is over six foot, that extra length is often the real reason to size up, since your feet are less likely to hang off the end.
Will a rolled king size mattress fit up narrow stairs?
The Komfi arrives vacuum packed in a roll, so the UK king travels as a compact bundle rather than a flat 5ft x 6ft 6in panel. That makes tight stairwells and landings much more manageable. Measure the stairs first, then compare the retailers listed on this page.
Should we get the Komfi Serenity Pocket 1000 in a king or a double?
Choose the UK king if you want 7.5cm more each and 10cm more length, and your room meets our suggested 2.7m x 2.9m. The UK double suits a room of at least 2.6m x 2.8m. A dog that sleeps on the bed is another good reason to go for the UK king.