Harrison Spinks Diamond 25000 Pocket Small Double 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
£2,829
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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
- Real width for one: At 120cm wide, the UK small double is 30cm wider than the UK single, which means a solo sleeper can change position freely without an arm hanging off the edge.
- Fits a compact room: It's 15cm narrower than the UK double, so it slots into box rooms and loft conversions where a 4ft 6in frame would block walking space.
- Pocket springs for restless nights: Each spring compresses independently, which means you feel the surface respond to your own body rather than sagging toward the middle of a narrower bed.
- Medium feel, versatile support: The medium tension suits back and side sleepers alike, useful in a guest room where you can't predict who'll be sleeping on it.
- Easy to dress: 4ft is a standard UK size, so small double fitted sheets and frames are straightforward to find rather than specialist purchases.
This size suits you if...
You sleep alone and have outgrown a single but your room can't take a full double, you're furnishing a loft conversion or box room where every centimetre of floor matters, or you want a guest bed that couples can share for the occasional night. Allow at least 2.4m x 2.8m of floor space and the UK small double should sit comfortably.
Consider another size if...
You share the bed with a partner every night, because 120cm is a squeeze for two long term. We'd recommend the UK double instead, which is 15cm wider; allow at least 2.6m x 2.8m for that size.
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FAQ's
Is a small double Harrison Spinks Diamond 25000 big enough for a couple?
For occasional nights, yes. Two adults can share the UK small double for a weekend stay, and the pocket springs mean one person turning over shouldn't wake the other. For nightly sharing, 120cm is tight, and the UK double at 135cm wide would be the more comfortable long-term choice.
What room size do I need for the Diamond 25000 in a small double?
We suggest allowing at least 2.4m x 2.8m of floor space. That leaves enough room to walk around the bed and open drawers or a wardrobe. In smaller rooms, check the door swing clears the frame before you buy, particularly in lofts and studio flats.
How much bigger is the small double than the single in this mattress?
The UK small double is 30cm wider than the UK single, and both are the same length at 190cm. That extra width is the whole point: a solo sleeper gets noticeably more room to stretch without needing a bigger bedroom, since the footprint only grows in one direction.
What bedding fits the small double Diamond 25000?
Use small double (4ft) fitted sheets, as standard double sheets will bag at the corners. For the top layer, a standard double duvet works well and gives a generous overhang on each side, which suits a solo sleeper who likes plenty of cover.
Should I size up to the double instead of the small double?
If the room allows it, sharing nightly makes the UK double the better buy, as it's 15cm wider and needs at least 2.6m x 2.8m. If you sleep alone in a compact room, the UK small double gives you most of that comfort while keeping walking space either side.