Luna 4000 Plush Gel Memory Pocket Hybrid King Size Mattress
The Luna 4000 Plush Gel Memory Pocket Hybrid is a 25cm deep hybrid mattress that pairs a full pocket spring system with gel-infused memory foam, which means you get the contouring hug of foam without losing the responsive support of springs.
- Softer feel for side sleepers
- Mini springs fine-tune pressure relief
- Open-cell foam lets heat escape
£639
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Luna 4000 Plush Gel Memory Pocket Hybrid Mattress
More available sizes
Mattress details
Mattress
Luna 4000 Plush Gel Memory Pocket Hybrid Mattress
Size
Firmness
Medium Soft
Construction
Foam
Pocket Spring
Hybrid
Rolled
Memory Foam
Depth (cm)
25
Layers
5
Layer Details
Knitted cover
A soft knitted top designed to enhance airflow and breathability. It adds a cosy, slightly plush first impression when you lie down.
Luna Fusion Cool Memory Foam
A 2cm layer of open cell memory foam, which means it lets heat escape more readily than standard memory foam while still moulding to your shape. It provides that gentle, cradled feel memory foam is known for.
Reflex Foam
Two 3cm layers of supportive foam that mould to your body and help keep your spine aligned. This is the transition zone between the soft top and the springs below.
Mini Pocket Springs
Small, individually cased springs that add a layer of fine-tuned pressure relief and reduce motion transfer, which means less disturbance when a partner shifts in the night.
Luna Pocket Springs
Full-size steel springs sewn into individual fabric pockets, each responding independently to your weight and movement. This is the mattress's main support system, keeping your body properly aligned.
Layer details from mattressonline.co.uk product page, September 2026.
Key benefits
- 75cm of width each: Two people sharing get 75cm apiece, which means you can sink into the plush top without drifting into your partner's half.
- Less disturbance at different hours: The mini pocket springs reduce motion transfer, so a partner leaving hours before you is far less likely to wake you across a 150cm width.
- Extra length for taller sleepers: At 200cm, the UK king is 10cm longer than the UK double, welcome relief if either of you is approaching 6ft.
- Room for restless nights: During pregnancy or recovery from an injury, when you're propping pillows and shifting position, the wider surface and gentle contouring give you space to rearrange without a negotiation.
- A realistic fit for most masters: We suggest a room of at least 2.7m x 2.9m, achievable in most main bedrooms, unlike the UK super king's larger demands.
This size suits you if...
You share the bed every night and a double now feels tight, one of you is tall enough that your feet hover near the end of a 190cm mattress, or your sleep schedules rarely line up and you want the width and motion isolation to stop early alarms travelling. Lighter sharers and side sleepers get the most from this softer feel at this size.
Consider another size if...
Your bedroom is under our suggested 2.7m x 2.9m minimum, or you sleep alone and don't need 150cm of width. We'd recommend the UK double instead, which needs a slightly smaller room at 2.6m x 2.8m.
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FAQ's
Is a UK king big enough for a couple on the Luna 4000?
Yes, comfortably for most. You get 75cm each, and because the Luna 4000's soft to medium feel lets shoulders and hips sink in, that personal width helps you settle without crowding each other. Very broad sharers, or anyone who wants a dog on the bed as a permanent fixture, may prefer the UK super king.
Will the Luna 4000 king stop me feeling my partner get up?
It should help noticeably. The mini pocket spring layer sits above the full-size springs specifically to reduce motion transfer, and the 150cm width puts more distance between you. Across a UK king, one of you leaving for an early shift is much less likely to wake the other than on a narrower double.
Is the Luna 4000 in a UK king long enough for someone over 6ft?
At 200cm, or 6ft 6in, the UK king gives a tall sleeper meaningful clearance. It's 10cm longer than the UK double, which is often the difference between feet on the mattress and feet hanging off. Anyone around the 6ft mark should find the length generous rather than tight.
What room size does a king mattress need?
We suggest at least 2.7m x 2.9m for a UK king. That allows walking space on both sides and the door to open freely. New build masters can be smaller than they look once wardrobes go in, so measure the usable floor, not the wall to wall figure, before committing.
Should I get the Luna 4000 in a king or a super king?
The UK king is 30cm narrower than the UK super king, and the two are the same length. If your room meets the 3m x 2.9m we suggest for a UK super king and you want maximum sprawl, size up. If space or budget is tighter, the UK king remains the sensible upgrade for most couples.