Harrison Spinks Diamond 25000 Pocket Super King Mattress (Medium Feel)
The Harrison Spinks Diamond 25000 is a pocket spring mattress in a medium feel, which means it aims to balance cushioning with support rather than sitting at either extreme.
- Medium feel suits back & side sleepers
- Individually responsive springs
- From a long-established British maker
£3,929
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Harrison Spinks Diamond 25000 Pocket Mattress (Medium Feel)
More available sizes
Mattress details
Mattress
Harrison Spinks Diamond 25000 Pocket Mattress (Medium Feel)
Size
Firmness
Medium
Construction
Pocket Spring
Wool
Natural
Depth (cm)
Layers
6
Layer Details
Cortec Quad pocket springs
The core has 700 Cortec Quad springs, held in groups of four within a single fabric pocket, in a glue-free design. This gives the mattress its supportive base while each group can still respond to your body on its own.
Mini pocket springs
Layers of 24300 mini springs sit above the core and give more points of contact with your body. That means the surface can follow your shape more closely.
British wool comfort layers
Layers of British wool add snug, cushioned comfort over the springs. They soften the feel without relying on foam.
Wool, mohair and cashmere layer
A layer of wool, mohair and cashmere is added to enhance the indulgent feel. You should notice it as a softer, more cosseting surface.
Wool, hemp and flax layer
A blend of British wool, hemp and flax fibres increases durability within the comfort layers. The aim is to help the mattress keep its feel as it is used.
Cotton, hemp and flax layer
Additional layers of cotton, hemp and flax fibres wick away moisture. That should help the mattress feel drier and fresher through the night.
Layer details from harrisonspinks.co.uk and mattressonline.co.uk product pages, October 2026.
Key benefits
- 90cm each for two sharing: Each of you gets 90cm of width, so one person turning over, or reading late, is far easier for the other to ignore.
- Pocket springs suit a shared bed: Springs that compress individually mean movement on one side stays on that side, which pairs well with the extra distance a UK super king already provides.
- Room for night-time visitors: If children pad through at 3am, or a large dog treats the bed as home, 180cm of width means everyone still gets a workable share.
- Medium feel across a wide surface: A medium feel suits most back and side sleepers, useful on a bed this size where two people rarely want the same firmness compromise.
- Made for larger bedrooms: In a big master or period bedroom a UK king can look lost; the UK super king fills the space properly, provided you allow at least 3m x 2.9m.
This size suits you if...
You share the bed every night with a partner who fidgets, and distance has become more valuable than any comfort layer. Children or pets regularly join you and you want everyone to keep a fair share. Or your master bedroom is large enough that anything smaller would look undersized, and you can comfortably allow at least 3m x 2.9m of floor space.
Consider another size if...
Your bedroom falls short of the 3m x 2.9m we suggest, or your landing and door swing make a 180cm-wide mattress a struggle to deliver. The UK king is 30cm narrower at the same length, and needs a smaller room, at least 2.7m x 2.9m.
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FAQ's
Is a super king too big for my bedroom?
It might be. We suggest at least 3m x 2.9m for a UK super king, and that is a minimum rather than a comfortable fit. Measure with bedside tables in place and check the door can open fully. If the room is tight, the UK king is 30cm narrower, the same length, and needs at least 2.7m x 2.9m.
Is the Diamond 25000 in a super king good for restless couples?
It is one of the better cases for the size. Pocket springs respond to each sleeper individually, so movement transfers less than on an open-coil bed, and the UK super king adds 90cm of width per person on top. Between the two, a partner who shifts around all night becomes much easier to sleep through.
Will a super king mattress get up my stairs?
This is the check that bites at 180 x 200cm. A pocket spring mattress like the Diamond 25000 has limited flex, so measure your staircase, any landing turns and the bedroom doorway before ordering. If access is genuinely awkward, ask the retailer about delivery options; the prices shown on this page link to retailers who can advise.
How much wider is a super king than a king?
The UK super king is 30cm wider than the UK king, and the two are the same length at 200cm. That 30cm all goes into personal space: 90cm each for two people sharing. If children or pets join you at night, that extra width is usually the difference between comfortable and cramped.
Is this a sensible size if children climb in at night?
Yes, it is the size we would point families towards. At 180cm wide, a child arriving in the small hours can settle between you without pushing either adult to the edge, and the pocket springs keep their wriggling from travelling across the bed. On anything narrower, regular visitors tend to mean someone gives up and moves.