Harrison Spinks Diamond 25000 Pocket King Size 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
£3,149
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Harrison Spinks Diamond 25000 Pocket Mattress (Firmer Feel)
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Mattress details
Mattress
Harrison Spinks Diamond 25000 Pocket Mattress (Firmer Feel)
Size
Firmness
Firm
Construction
Pocket Spring
Wool
Natural
Depth (cm)
Layers
6
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.
Key benefits
- Room for two to sleep separately, together: With 75cm each for two people sharing, you can both change position without negotiating for territory in the middle of the night.
- Pocket springs earn more in a wider bed: Independent springs mean movement stays local, so a partner getting up hours before you is less likely to wake you across a 150cm width.
- Extra length for taller sleepers: At 200cm, the UK king is 10cm longer than the UK double, which stops feet hanging off the end for anyone approaching six foot.
- A firm feel that holds across the full width: The catalogued firm feel gives back and front sleepers consistent support edge to edge, useful when two people spread out rather than sharing the centre.
- Fits most master bedrooms: We suggest a room of at least 2.7m x 2.9m, which most UK master bedrooms can manage where a super king would feel cramped.
This size suits you if...
You share the bed every night and a double has started to feel like a compromise, especially if one of you keeps different hours and the other wants to sleep through the early exit. It also suits couples where one partner is approaching six foot, since the 200cm length removes the cramped feeling a 190cm double can give a taller back or front sleeper.
Consider another size if...
Your bedroom is under our suggested 2.7m x 2.9m minimum, or you sleep alone and the firm feel is the only draw. We'd recommend the UK double instead, which needs a room of at least 2.6m x 2.8m.
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FAQ's
Is the Diamond 25000 in a UK king big enough for a couple?
Yes, comfortably for most. The UK king gives 75cm each for two people sharing, and because this is a pocket spring mattress, each spring compresses independently, so one sleeper's movement stays largely on their side. If one of you is broad-shouldered or you share with a pet, the UK super king adds another 30cm of width.
Will the UK king suit a tall sleeper?
At 200cm long, the UK king suits sleepers approaching six foot who find a standard 190cm mattress leaves their feet at the edge. There's no need to size up for height alone: the UK king and the UK super king are the same length, so the super king only adds width, not extra room to stretch out lengthways.
What room size do I need for the Diamond 25000 in a UK king?
We suggest a room of at least 2.7m x 2.9m, which leaves enough space to walk round the bed and open drawers. That guidance is ours rather than the manufacturer's. If your room falls short, the UK double version of this mattress needs at least 2.6m x 2.8m and still gives a couple a workable amount of space.
Does a king size help with partner disturbance on this mattress?
It helps on two fronts. The pocket spring construction absorbs movement locally rather than transferring it across the bed, and the 150cm width puts more distance between you, so an early riser or a restless sleeper is less likely to wake their partner. Neither makes movement invisible, but together they make a real difference to light sleepers.
Should I choose the Diamond 25000 in a UK king or super king?
The UK king suits most couples and most rooms. The UK super king is 30cm wider, worth having if you share with children or a dog, or you both like to spread out, but it demands a room of at least 3m x 2.9m. Both sizes are the same length, so height isn't a reason to size up.