Firmness
Firm
Type
Pocket Spring
Depth (cm)
Number of Layers
Trial Period (nights)
Warranty (years)
Price Range
£2,049 to £3,929
Best Sleeping Position(s)
Certifications
Assessed from the product page published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
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 & what's inside
Awaiting up to date specifications. Please check back later.
Who's it NOT for?
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.
Harrison Spinks Diamond 25000 Pocket Mattress (Firmer Feel)
View all mattresses
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. Prices range from £2,049 to £3,929 depending on the size you choose.
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.
Couldn't find an answer to your question? Send us a message