Firmness
Medium Soft
Type
Pocket Spring
Depth (cm)
32
Number of Layers
7
Trial Period (nights)
100
Warranty (years)
5
Price Range
£2,049 to £3,929
Best Sleeping Position(s)
Certifications
Assessed from the specification published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
This mattress makes sense if natural materials matter to you. There's no foam in the layer list: instead you get cotton, hemp, flax, British wool, mohair and cashmere, fillings that breathe and wick moisture, which means less of the clammy warmth some synthetic mattresses trap. The spring system is unusually intricate, with 24,300 mini springs above 700 Cortec Quad springs, each group of four secured within one fabric pocket, so pressure relief feels precise rather than general. It's a National Bed Federation Approved Brand and the mattress conforms to BS7177: 2008 for home use. Yes, the price is high, but the depth, handcrafting and quality of fillings go some way to justifying it. Mattress Online lists a 100-night trial and a 5-year guarantee.
Key Features & what's inside
- Comfort Layer - Top Surface (Summer Side). The summer side puts moisture wicking cotton closest to you. In practice that means a cooler, drier feel on warm nights.
- Comfort Layer - Moisture Wicking Blend. Further layers of cotton, hemp and flax fibres draw moisture away from your body. This adds to that refreshing feel rather than letting heat and dampness build up.
- Comfort Layer - Breathability Blend. A blend of British wool, hemp and flax fibres improves durability within the comfort layers. Natural fibres like these tend to hold their loft well over time.
- Comfort Layer - Luxury Blend. Wool, mohair and cashmere sit here to deepen the indulgent feel. These are the fillings that give the surface its soft, expensive-feeling finish.
- Comfort Layer - British Wool. Layers of British wool provide snug, cushioned comfort. Wool also regulates temperature naturally, which helps across the seasons.
- Support Layer - Mini Pocket Springs. 24,300 mini springs create many more points of contact with your body. That means comfort delivered exactly where you need it, with less of the hammocking a coarser spring layer can cause.
- Support Layer - Cortec Quad Springs. 700 of Harrison Spinks' award-winning Cortec Quad springs form the core, secured in groups of four within one fabric pocket. This grouped design gives responsive, stable support at the base of the mattress.
Layer details from mattressonline.co.uk product page, September 2026.
Who's it NOT for?
If you prefer a firm surface or sleep mostly on your front, the soft to medium feel here is unlikely to give you the resistance you want. Budget shoppers should also pass: at £2,049 upwards this is a serious outlay. And if you can't manage turning a heavy 32cm mattress, the seasonal turn design may prove awkward.
Harrison Spinks Diamond 25000 Pocket Mattress (Soft to Medium Feel)
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How firm is the Harrison Spinks Diamond 25000?
It has a soft to medium feel. That gentle surface suits side sleepers and anyone who likes a cushioned, enveloping sleep position, although heavier sleepers or those who prefer a firmer platform may find it a little too yielding.
How many springs does the Diamond 25000 have?
The listing details 24,300 mini pocket springs in the support layers plus 700 Cortec Quad springs at the core, secured in groups of four within a single fabric pocket. That combination gives many small points of contact for precise pressure relief.
Does the Harrison Spinks Diamond 25000 come with a trial?
Mattress Online lists a 100-night trial and a 5-year guarantee for this mattress. Those are the retailer's own terms, so if you buy elsewhere, check that seller's trial and guarantee before ordering.
Do you need to flip the Harrison Spinks Diamond 25000?
The retailer's description presents it as double-sided with a seasonal turn design, including a summer side with moisture wicking cotton. The listing's specification table is contradictory on this point, so it's worth confirming with the retailer before you buy.
How much does delivery cost for the Diamond 25000?
Mattress Online offers free delivery within 7 weeks to the front door of your building across mainland England and most of Scotland, Wales and Northern Ireland. Delivery to your room of choice costs £20, and old mattress recycling is available for £35.
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