Harrison Spinks Diamond 25000 Pocket Super King Mattress (Soft to Medium Feel)
The Harrison Spinks Diamond 25000 is a pocket spring mattress with a soft to medium feel, handcrafted in the UK and filled with natural materials including British wool, cashmere, mohair, hemp and flax.
- Foam-free, all-natural fillings
- Precise, targeted pressure relief
- Wicks moisture for cooler, drier nights
£3,929
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Harrison Spinks Diamond 25000 Pocket Mattress (Soft to Medium Feel)
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Mattress details
Mattress
Harrison Spinks Diamond 25000 Pocket Mattress (Soft to Medium Feel)
Size
Firmness
Medium Soft
Construction
Pocket Spring
Wool
Natural
Depth (cm)
32
Layers
7
Layer Details
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.
Key benefits
- Real distance from a fidgety partner: With 90cm each, a partner who turns all night is simply further away, and the 24,300 mini springs localise movement rather than transmitting it across the bed.
- Room for children and pets: When a child wanders in at 3am, or a large dog treats the bed as routine, the extra width means everyone still gets a workable share.
- A soft feel that spreads out: The gentle, cushioned surface of wool, mohair and cashmere is easier to enjoy when you can stretch fully without touching the edge or each other.
- Suits a larger master bedroom: In a period property or generous new build master, a UK super king fills the room properly where a UK king can look undersized against the wall.
- Natural fillings across a bigger surface: Cotton, hemp, flax and British wool breathe and wick moisture, so two people sharing generate less trapped warmth than a synthetic mattress this size might.
This size suits you if...
You share the bed every night and one of you is a light sleeper, a restless sleeper, or both; children or pets regularly join you and you want everyone to keep a fair share; or your bedroom is large enough that a UK king would look and feel undersized. It also suits you if you want the Diamond 25000's soft, natural-filled surface with the maximum room to spread out.
Consider another size if...
Your bedroom is under our suggested 3m x 2.9m minimum, or you'd struggle to turn a 32cm deep mattress at this width. We'd recommend the UK king instead: it's 30cm narrower, the same length, and we suggest at least 2.7m x 2.9m for it.
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FAQ's
What room size do I need for the Diamond 25000 in a UK super king?
We suggest a room of at least 3m x 2.9m. That's our guidance rather than the manufacturer's, and it assumes bedside tables on both sides plus space to walk around the bed. Anything smaller and the room starts to feel like storage for the mattress rather than a bedroom.
Is the super king Diamond 25000 difficult to turn?
It's the size where the seasonal turn design demands the most respect. At 32cm deep and 180cm wide, with dense natural fillings rather than foam, this is a two-person job. If you live alone or have back trouble, factor that in before choosing this size, or size down.
How much wider is the UK super king Diamond 25000 than the UK king?
The UK super king is 30cm wider than the UK king, and the two are the same length. That extra width takes each sharer from a comfortable allowance to 90cm each, which is where a genuinely restless partner stops being your problem at night.
Does a couple really notice the extra space in a super king?
Yes, especially with a soft to medium mattress like this one. You each get 90cm, so you can settle into the cushioned wool and cashmere layers without drifting towards the middle. The 24,300 mini springs also respond to each sleeper separately, so one person's movement disturbs the other less.
Will the Diamond 25000 super king get up my stairs?
Measure before you order. A 180 x 200cm mattress at 32cm deep is awkward on tight landings and narrow turns, and pocket spring construction doesn't roll or fold the way foam can. Check door swings, stairwell width and any low ceilings on the route to the bedroom first.