Luna 4000 Support Gel Memory Pocket Hybrid King Size Mattress
The Luna 4000 Support Gel Memory Pocket Hybrid is a 25cm deep hybrid with a medium to firm feel, combining memory foam over a total of 4,000 springs, made up of 2,000 mini pocket springs sitting above a core of 2,000 full-size Luna Pocket springs.
- Support where your body needs it
- Minimises partner disturbance
- Contours without the heat build-up
£669
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Luna 4000 Support Gel Memory Pocket Hybrid Mattress
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Mattress details
Mattress
Luna 4000 Support Gel Memory Pocket Hybrid Mattress
Size
Firmness
Medium Firm
Construction
Foam
Pocket Spring
Hybrid
Memory Foam
Gel
Depth (cm)
25
Layers
4
Layer Details
Luna Fusion Cool Memory Foam
A 2cm layer of memory foam that adapts around your body, which means gentle pressure relief where you need it. Its breathable, open cell structure lets air move through, giving a cooler, fresher feel than standard memory foam.
Reflex Foam
Two 3cm layers of Reflex foam add cushioning for extra comfort, which means a slightly softer landing before you reach the springs. They mould to your body and help keep your spine aligned.
Mini Pocket Springs
A layer of 2,000 mini springs gives a bouncy, comforting feel, so the mattress responds quickly when you change position. Their small size creates pockets of airflow and helps reduce motion transfer between partners.
Luna Pocket Springs
A core of 2,000 Luna Pocket springs, each encased in its own fabric pocket. They respond individually to changes in weight and movement, which means support is distributed exactly where your body needs it.
Layer details from mattressonline.co.uk product page, September 2026.
Key benefits
- Proper space for two: At 75cm each for two people sharing, you can both stretch out without negotiating the middle of the bed.
- Movement stays on their side: Pocket springs that respond individually plus the wider 150cm footprint mean an early alarm on one side is less likely to travel across to yours.
- Length for taller sleepers: The UK king is 10cm longer than the UK Double at 200cm, so anyone approaching six foot stops sleeping diagonally.
- Firm support across the full width: The medium firm feel and 4,000-spring construction hold their shape edge to edge, useful when a dog or a small child claims part of the mattress.
- Cool where you actually lie: The open cell memory foam runs cooler than standard memory foam, and with 75cm each you're less likely to share body heat anyway.
This size suits you if...
You share the bed every night and a UK double leaves you elbow to elbow, one of you is close to six foot and keeps meeting the footboard, or you and your partner keep different hours and want getting up early to go unnoticed by the person still asleep.
Consider another size if...
Your bedroom is under our suggested 2.7m x 2.9m minimum, or you mostly sleep alone. We'd recommend the UK double of this mattress instead, and for that size we suggest allowing at least 2.6m x 2.8m.
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FAQ's
Is the Luna 4000 in a UK king big enough for a couple?
Yes, comfortably for most. The UK king measures 150 x 200cm, which gives 75cm each for two people sharing. Combined with the pocket springs that respond to each sleeper's weight individually, that width means one restless partner is less likely to disturb the other. Owners describe the feel as firm, so expect support rather than sink.
What size room do I need for the Luna 4000 UK king?
We suggest a room of at least 2.7m x 2.9m, which leaves enough space to walk round the bed and open drawers. That guidance is ours rather than Luna's. If your room is a new build master that shrinks once the wardrobes go in, measure with furniture in place before deciding.
Is the Luna 4000 UK king long enough for tall sleepers?
At 200cm, or 5ft x 6ft 6in in imperial, the UK king is 10cm longer than the UK Double. For anyone approaching six foot, that extra length is often the real reason to size up, since it stops feet hanging off the end without demanding the room space a UK super king needs.
Will a king size Luna 4000 help if my partner gets up earlier than me?
It should. The core of 2,000 Luna Pocket springs responds to movement individually rather than as one surface, and the 150cm width puts more mattress between you. Together those make an early exit from the other side of the bed noticeably easier to sleep through than on a narrower size.
Where can I compare prices for the Luna 4000 in a UK king?
Use the retailer table on this page. The prices shown here are updated as retailers change them, so it's the quickest way to see what the UK king currently costs. Availability can differ between sizes, so what you see for the UK king may differ from the UK double or UK super king.