Harrison Spinks Diamond 25000 Pocket King Size 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
£3,149
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Harrison Spinks Diamond 25000 Pocket Mattress (Medium Feel)
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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
- 75cm of width each: Two people sharing get 75cm each, so a partner shifting or getting up early is less likely to pull you out of sleep.
- Pocket springs plus space: Each spring compresses independently, which means movement on one side travels less, and the UK king's width adds physical distance on top.
- 15cm wider than a UK double: That difference is felt at the shoulders every night, particularly if you both like to sprawl or one of you props pillows.
- 200cm of length: The UK king adds 10cm of length over the UK double, welcome relief if either of you is approaching six foot.
- A medium feel two can share: A medium tension suits a wide range of sleepers, useful when a couple upgrading sizes has slightly different preferences.
This size suits you if...
You share the bed every night and a double has started to feel cramped, especially if one of you moves a lot or keeps different hours. The 200cm length also matters if either of you is tall, since a standard double is 10cm shorter. And your bedroom comfortably clears our suggested minimum of 2.7m x 2.9m for a UK king.
Consider another size if...
You sleep alone, or your room falls short of 2.7m x 2.9m. In that case we'd recommend the UK double instead, which needs around 2.6m x 2.8m and costs less at this premium price level.
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FAQ's
Is the Diamond 25000 in a UK king good for couples?
It's a strong pairing. Across the range the pocket spring construction lets each side respond independently, and the UK king adds 75cm of width per person, so a restless or early-rising partner disturbs you less. Given the premium price, couples who share every night will get the most from the extra space.
How much bigger is the UK king than the double in this mattress?
The UK king is 15cm wider and 10cm longer than the UK double. The width is the difference you notice nightly with two of you sharing, while the extra length helps taller sleepers whose feet reach the end of a 190cm double.
Will a UK king Diamond 25000 fit my bedroom?
We suggest a room of at least 2.7m x 2.9m for a UK king, which leaves space to walk round and open drawers. Newer master bedrooms can be tighter than they look once wardrobes go in, so measure the usable floor, not the full room.
Is the UK king long enough for someone over six foot?
At 200cm, or 6ft 6in end to end, it suits most tall sleepers comfortably. If one of you is over six foot and you're upgrading from a double, the extra 10cm of length is often the change you feel first, before the width.
Should we choose the UK king or the UK super king?
The UK super king is 30cm wider than the UK king, with the same 200cm length, but it needs a room of at least 3m x 2.9m. If your room clears that and you want the most personal space, size up; otherwise the UK king is the more practical choice.