Harrison Spinks Diamond 25000 Pocket Mattress (Firmer Feel)
The Harrison Spinks Diamond 25000 is a firm pocket spring mattress whose springs move independently, so it responds to your shape and limits the ripple when a partner shifts.
- Firm feel for back & front sleepers
- Tends to sleep cooler than all-foam
- Supportive pocket sprung surface
£2,049
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The Harrison Spinks Diamond 25000 comes in five UK sizes, from Single up to Super King. It sits firmly at the premium end of the market, so it makes most sense if you want a firmer, spring-led feel and are prepared to pay for traditional pocket spring construction rather than foam.
Mattress specifications
Firmness
Firm
Type
Pocket Spring
Depth (cm)
Number of Layers
6
Trial Period (nights)
Warranty (years)
Price Range
£2,049 to £3,929
Best Sleeping Position(s)
Back Sleeping
Stomach Sleeping
Certifications
Assessed from the product page published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
Why should you choose this mattress?
If you sleep on your back or front and like a firm, supportive surface, this catalogued firm feel is the main draw. Pocket springs also tend to sleep cooler than all-foam designs, which means hot sleepers may find it a more comfortable choice through warmer months. The retailer listing includes a 5 year guarantee, shorter than some brands offer, though that term is the retailer's rather than a universal promise. One thing to check before you buy: the model is sold in more than one firmness variant, so confirm with the retailer that you are ordering the firm version, not the softer options also listed.
Key features & layer details
Wool and viscose
The top layers are a blend of British wool and viscose. This is the first thing you feel when you lie down, so it sets the soft, natural surface over the springs beneath.
Wool and mohair
A British wool and mohair blend sits below. It adds another natural layer of cushioning between you and the spring unit.
Cashmere
A cashmere layer comes next. It adds a soft natural fibre to the mix, so the surface feels less stark than a firm spring mattress might suggest.
Yorkshire wool, silk and British wool
This layer blends Yorkshire wool, silk and British wool. It continues the all-natural filling, adding to the comfort layers that sit over the springs.
Wool, hemp and flax
A British wool, hemp and flax blend that increases durability and breathability. For you, that means a filling that should hold up well over time and let air move through.
Cotton, hemp and flax
A cotton, hemp and flax blend that wicks away moisture. It helps keep the sleeping surface drier, which is useful if you sleep warm. Hemp and flax fibres are also hypoallergenic and antimicrobial.
Layer details from harrisonspinks.co.uk and mattressonline.co.uk product pages, October 2026.
Best suited for?
Back sleepers
The firm feel gives a supportive, flat surface under the body, which suits anyone who lies on their back and prefers little sink.
Front sleepers
A firm, spring-led surface keeps the body from sinking in too deeply, which is what many front sleepers want from a mattress.
Warm sleepers
Pocket spring construction tends to sleep cooler than all-foam designs, so you may find it more comfortable through the warmer months.
Combination sleepers
Firm pocket springs make it easy to move between positions, though side sleeping may feel less cushioned, so it suits those who mostly turn between back and front.
Lightweight side sleepers may find a firm mattress a little unforgiving on the shoulders and hips, where you need some give for pressure relief. It is also a significant spend, so if your budget is tighter there are capable pocket spring options for less. Anyone wanting a plush, cushioned surface should look elsewhere.
Save on an earlier or ex-display model
Some retailers still sell the earlier version of this mattress, or ex-display and returned stock at a lower price. These are the sizes where it costs less than the current model's best price.
Harrison Spinks Diamond 25000 Pocket Mattress (Firmer Feel)
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FAQ's
How firm is the Harrison Spinks Diamond 25000?
This version is listed as firm. Be aware the model is sold in more than one firmness variant, so it's sensible to confirm the exact feel with the retailer before ordering, particularly if you specifically want the firmer option.
What sizes does the Diamond 25000 come in?
It's available in five UK sizes: Single, Small Double, Double, King and Super King.
Does the Harrison Spinks Diamond 25000 have a guarantee?
The retailer listing includes a 5 year guarantee. As this is a retailer's stated term rather than the brand's own page, check the guarantee that applies wherever you actually buy.
Is the Diamond 25000 a pocket spring mattress?
Yes. Pocket springs are individually wrapped coils that compress independently, which means better contouring to your body and less motion transfer than open-coil designs, so a restless partner is less likely to disturb you.
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