Harrison Spinks Platinum 12500 Pocket Mattress (Firmer Feel)
Mattress
Harrison Spinks Platinum 12500 Pocket Mattress (Firmer Feel)
Size
Firmness
Firm
Construction
Depth (cm)
29
Layers
6
Layer Details
- Comfort fillings. Layers of plush British wool sit at the top, which means natural temperature regulation. You should feel cosy in winter and cooler in summer.
- Comfort fillings blend. Cotton and wool fibres are blended with hemp and flax. These tougher plant fibres help the comfort layers keep their shape over time.
- Ecotex layer. A layer of Ecotex fibres made from recycled materials. It adds strength and durability rather than a feel you'd notice directly.
- Mini Pocket Springs. Layers of 10,500 mini springs contour to your body. Because each spring moves independently, the surface adapts to your shape for a more personalised feel.
- Posturfil springs. An additional 1,000 Posturfil springs respond to your movements and how your weight is distributed. In practice, this means flexible support that adjusts as you change position.
- Cortec Quad Revolution springs. The base layer of 1,000 Cortec Quad Revolution springs adapts to your body for deeper support. Each one has a mini spring inside it, so you get two stages of response from a single spring.
Layer details from mattressonline.co.uk product page, September 2026.
- Room to spread out alone: At 120cm wide, the UK small double gives a solo sleeper generous space to shift position without the footprint of a full double.
- Fits rooms a double overwhelms: Being 15cm narrower than the UK double, it can be the difference between a bed that fits a box room and one that blocks the door.
- Natural fillings across a wide surface: British wool, cotton, hemp and flax regulate temperature, which means a solo sleeper spreading across the full width stays at a steadier temperature all night.
- 12,500 springs contour to one body: Three spring layers adapt to weight and movement, so a lone sleeper gets contouring across the whole 120cm rather than a worn central channel.
- Standard 4ft sizing: The small double is a standard UK size, so frames and fitted sheets are straightforward to find when you're kitting out a smaller room.
- Practical for occasional sharing: Two people can manage a night or two, which makes it a sensible spend for a guest room that hosts couples now and then.
This size suits you if...
You sleep alone and have outgrown a UK single but can't spare the floor space a double demands, your box room, studio or loft conversion needs every centimetre of walking room, or you're furnishing a guest room where couples stay occasionally rather than nightly. Allow at least 2.4m x 2.8m of floor space and this size should sit comfortably.
Consider another size if...
You share the bed every night, because 120cm is a squeeze for two adults long term. We'd recommend the UK double instead, which is 15cm wider and the same length; allow at least 2.6m x 2.8m for it.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
Is a small double big enough for one adult on the Platinum 12500?
Yes, comfortably. The UK small double is 30cm wider than the UK single, so a solo adult gets real room to sprawl, and the 12,500 springs respond independently across that width. If you tend to move around a lot in the night, it's a noticeable upgrade from a single without needing a bigger room.
Can a couple sleep on the small double Platinum 12500 every night?
We wouldn't suggest it for nightly sharing. At 120cm wide, two adults get less personal space than each would have on a UK single. For occasional guest room stays it works fine, and the independent pocket springs limit disturbance when one person moves. Full-time couples should look at the UK double or UK king pages of this mattress.
What room size do I need for the small double Platinum 12500?
We suggest allowing at least 2.4m x 2.8m of floor space. That gives you room to walk around the bed and open drawers or doors. The mattress itself is 120 x 190cm and 29cm deep, so check your headboard height and any sloping loft ceilings too, since it's a taller mattress than many.
How much smaller is this size than the double version?
The UK small double is 15cm narrower than the UK double, and the two are the same length. That 15cm sounds minor but often decides whether a door still clears or a wardrobe still opens in a compact bedroom. If your room can take the wider frame, we'd lean towards the UK double for regular sharing.
Where can I check the price of this size?
Prices for the small double change as retailers update them, so we don't print figures here. The live table on this page shows current prices for the Harrison Spinks Platinum 12500 in the UK small double, refreshed as retailers change them, which is the most reliable way to compare before you buy.