Harrison Spinks Ruby 12500 Pocket Mattress (Firmer Feel)
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Mattress
Harrison Spinks Ruby 12500 Pocket Mattress (Firmer Feel)
Size
Firmness
Firm
Construction
Pocket Spring
Wool
Natural
Depth (cm)
Layers
5
Layer Details
Mini pocket springs
Small, individually cased springs sit in the comfort layer and add cushioning while cutting down motion transfer. In practice, you get a little give on top of the firm feel, and less disturbance when a partner moves.
Wool
Wool comfort filling, described as a natural insulator with temperature-regulating properties. It helps keep you from getting too warm or too cool as the night goes on.
Cotton
Natural cotton fibres create a fresh sleeping environment and wick away moisture. That should help the surface feel drier and fresher, especially if you tend to sleep warm.
Hemp
Hemp is an eco-friendly fibre that is naturally breathable and durable. It lets air move through the filling and should help the mattress keep its feel over time.
Flax
Flax fibres are durable and breathable, and are described as having anti-bacterial properties. This is a hard-wearing natural layer that adds to the airy feel of the fillings above it.
Layer details from mattressonline.co.uk and simplybedssussex.co.uk product pages, October 2026.
- Real width for one sleeper: At 120cm across, the UK small double is 30cm wider than a UK single, which means you can stretch, roll and change position without meeting the edge.
- Fits rooms a double cannot: It is 15cm narrower than a UK double, which can be the difference between a door that clears and one that scrapes in a box room or loft conversion.
- Firm support at full spread: Pocket springs respond to each part of your body individually, so a solo sleeper lying diagonally still gets even, firm support rather than a tilt towards the middle.
- Sensible for occasional sharing: A visiting couple can manage a night or two comfortably, and the firm feel keeps the surface stable when two people share the narrower width.
- Standard 4ft sizing: The small double is a common UK size, so frames, fitted sheets and headboards are easy to find rather than special-order items.
This size suits you if...
You sleep alone and have outgrown a single, but your room cannot give up the floor space a UK double demands. Or you're furnishing a compact second bedroom, a studio or a loft conversion where 15cm of width decides whether the layout works. It also fits a guest room that hosts the occasional couple rather than anyone every night, provided a firm feel suits your visitors.
Consider another size if...
You share the bed every night and want proper space for two adults long term. We'd recommend the UK double of this mattress instead: it is 15cm wider and the same length, and we suggest at least 2.6m x 2.8m of room for it.
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Is a small double big enough for a teenager who has outgrown a single?
Yes, comfortably. The UK small double is 30cm wider than a UK single and the same 190cm length, so a growing teenager gains real stretching room without the bed swallowing the floor space they need for a desk or wardrobe. Just weigh the firm feel: lighter side sleepers may find it a little unyielding at the shoulder.
Will the small double Ruby 12500 fit in a box room?
Usually, yes. We suggest a minimum room of 2.4m x 2.8m for a UK small double, which leaves enough space to walk round the bed and open the door. Measure the wall the bed will sit against and check clearance for the door swing before ordering, since 120cm of width plus a frame adds up quickly.
Can a couple use the small double Ruby 12500 in a guest room?
For occasional stays, yes. Two adults will find 120cm snug for nightly use, but for a guest room that hosts couples a few times a year it works well, and the firm pocket spring surface stays stable rather than rolling both sleepers together. If guests will stay for long stretches, the UK double is the safer pick.
What is the price of the Ruby 12500 in a UK small double?
Prices change often, so we don't print a figure here. The live table on this page shows current retailer pricing for the UK small double specifically, updated as retailers change it. It sits at the premium end of the market, so it suits buyers planning to keep the mattress for years rather than anyone shopping to a tight budget.
How much smaller is a small double than a king size?
The UK small double is 30cm narrower and 10cm shorter than the UK king, which measures 150 x 200cm against the small double's 120 x 190cm. If you're downsizing from a king into a smaller bedroom, that extra length matters too: taller sleepers lose 10cm of legroom, so check your height against the 190cm before deciding.