Last seen for £255 at Mattress Man on 30th October 2026
Arthur Sleep Cool Rock Double Mattress
The Arthur Sleep Cool Rock is a pocket spring mattress with a firm sleeping surface, which means noticeably more pushback than a medium feel and better spinal alignment if you sleep on your back or front.
- Extra-firm for back & front sleepers
- Support that follows your shape
- Minimises partner disturbance
Save with the previous model
Some retailers still sell the earlier version of this mattress for less than the current model's best price.
More available sizes
Last seen for £255 at Mattress Man on 30th October 2026
Mattress details
Mattress
Arthur Sleep Cool Rock Mattress
Size
Firmness
Extra Firm
Construction
Pocket Spring
Depth (cm)
Layers
Layer Details
Key benefits
- The standard couples' footprint: At 135 x 190cm, the UK double is the size most British bedrooms were designed around, so it fits without dominating the room.
- Firm support that suits sharing: Pocket springs move independently, which means one restless sleeper disturbs the other less, and the extra firm feel keeps both of you well aligned.
- Room for bedside tables: In a typical room, this width usually leaves space for a table on each side, which a UK king often takes away.
- Sensible for a guest room: An extra firm double copes well with visiting couples of varying builds, and its budget position makes it easy to justify for a room used occasionally.
- Easy to dress: Double sheets and 200 x 200cm double duvets are sold everywhere at every price, so bedding costs stay low alongside the mattress itself.
This size suits you if...
You share the bed every night and both of you like a firm, supportive surface, or you sleep alone and want space to spread out without stepping up to a bigger frame. It also makes sense if you're furnishing a whole home at once and need a proper couples' bed without stretching the budget, or you're kitting out a guest room for visiting pairs.
Consider another size if...
You and your partner both like to sprawl, because 67.5cm each is workable rather than generous. If your room allows at least 2.7m x 2.9m, we'd recommend the UK king instead, which is 15cm wider and 10cm longer.
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FAQ's
Is the Arthur Sleep Cool Rock double big enough for two adults?
Yes, for most couples. The UK double gives 67.5cm each for two people sharing, and because this is an extra firm pocket spring mattress, neither of you rolls towards the middle. Larger-framed couples, or restless sleepers who spread out, may find it snug and could consider the UK king, which is 15cm wider.
What room size do I need for the Cool Rock in a UK double?
We suggest at least 2.6m x 2.8m, with around 3m x 3m the comfortable norm. That allows walking space on both sides and, in most rooms, bedside tables too. If you're furnishing a first flat or second bedroom that also needs a wardrobe and drawers, the double's 135cm width usually leaves enough floor for both.
Will the extra firm feel work for couples of different weights?
Better than most feels at this price. Pocket springs respond to each sleeper independently, so a heavier partner won't create a slope the lighter one rolls into. That said, a lightweight side sleeper will still find the extra firm surface unforgiving on shoulder and hip, whichever side of the bed they're on.
Should I get the Cool Rock in a double or a king?
The UK double suits most shared bedrooms; the UK king is 15cm wider and 10cm longer, so it gives each of you more space but needs a room of at least 2.7m x 2.9m. If a king would crowd out your bedside tables or wardrobe doors, the double is the sensible pick.
Where can I buy the Arthur Sleep Cool Rock in a UK double?
Compare the retailers listed on this page; the prices shown here are updated as retailers change them. Availability can differ between the UK double and the other sizes, so it's worth checking the live table rather than assuming every size is stocked at the same time.