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Arthur Sleep Cool Rock Mattress

4.8/5
Body contouring gel foam tops an extra firm pocket sprung core that helps regulate temperature overnight.
iconExtra Firm
iconGel Foam
iconPocket Springs
icon24cm depth
  • Pocket Sprung Support
  • Body contouring gel foam
  • Body temperature regulation
  • Quilted fabric cover
Price Promise

Seen it cheaper somewhere else? We'll match it — that's our Price Promise.

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£249
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Description
Specifications
Dimensions
Available in 1 Showroom
1 Year Guarantee
Flexible Credit Options
Why This Mattress

Why buy the Arthur Sleep Cool Rock Mattress?

Every mattress is different. Scan for the ones that sound like you — if two or more fit, this is your mattress.

Best For
Back Sleepers
Sleep flat on your back?
Even, consistent support that keeps your spine in a natural position when lying on your back.
Helps with
Disturbance
Partner tosses and turns?
Springs that move independently absorb motion, so a restless partner is far less likely to wake you.
Helps with
Allergies
Wake up itchy or sneezy?
Hypoallergenic fillings and covers help keep dust mites and allergens at bay - ideal for allergy-prone sleepers.
Helps with
Pressure Relief
Achy hips or shoulders?
Cushioning comfort layers spread your weight evenly, easing pressure around hips and shoulders.
Helps with
Back Pain
Achy back in the morning?
A supportive, orthopaedic-grade build helps keep your spine aligned and takes the strain off your back.
Thermal Control
Cooling
Sleep hot?
Breathable layers draw heat away from you overnight, for a cooler sleep if you tend to run warm.
Suitability
Adults
Buying for a grown-up bed?
Built for full-grown sleepers, with the depth and support to take adult weight night after night.
How It Feels

How firm is it?

Extra Firm

Extra Firm is the level of support to the body, suitable for extra heavily weighted people. This is not a comfort rating.

About the Brand
4.82 brand rating

Arthur Sleep is an exclusive brand offering convenient, low-maintenance mattress solutions for all sleepers. With innovative pocket sprung and memory foam hybrids, they prioritize comfort and support. Featuring 100% hypoallergenic materials and a Which? Best Buy endorsement, Arthur Sleep ensures quality and restful nights for years.

View all Arthur Sleep
Real Sleepers

What our customers say

4.8
Product Rated 4.8 Stars
88 reviews
Average Customer Ratings
Comfort4.8
Durability4.8
Quality4.8
Value for money4.8
Rating Snapshot
5 stars
78
4 stars
4
3 stars
6
2 stars
0
1 stars
0
Excellent78
Great4
Average6
Laura Gulaszewska
Customer Rated This 5 Stars 5/5
29 Jan 2026
Omg... I never knew I'm going to love the mattress for SUCH A BARGAIN PRICE that much... First of all it took me over a year to finally choose and buy a mattress. I was looking at the price range from 500-1500 gbp. I wanted firm or super firm since I have a back and neck pain. By accident, the mattressman website came up with winter sale and I saw this one. ROCK ARTHUR. YEA... i would rather say King Arthur. It surprised me with a price (125) but also with many positive reviews from people who stopped suffering from pains. I ordered, with a 90 nights try and a protector, just in case I need to return. I unpacked, touched, lied on it... And omg I knew I'm not going to return this one. ABSOLUTELY WONDERFUL, HARD BUT NOT IN THE UNCOMFORTABLY HARD WAY THAT I THOUGHT. it's been over a week now. My back pain is gone. My neck and head ache is gone. I can't wait, like, literally can't wait to go to sleep every night. I love this mattress. Could give it 100 stars if possible. I only regret I didn't know that earlier.
Value5
Durability5
Quality5
Comfort5
J Baxter
Customer Rated This 5 Stars 5/5
20 Mar 2026
Now then, if you're looking for a bed that doesn't mess about, this Author Rock mattress is a champion choice. Here’s the lowdown after a month of use: The Verdict: Proper Firm If you like a mattress with a bit of backbone, this is the one for you. It’s proper firm—solid as a stone wall—which is exactly what I was after. For the brass it costs, the value is grand; you’d be hard-pressed to find something this sturdy without paying a fortune. Support & Comfort Edge Support: It’s reet solid. You can sit right on the edge to put your socks on without feeling like you’re going to slide onto the floor. The Setup: Because it’s so firm, I’ve paired it with a topper. It just adds that little bit of extra comfort while keeping the support underneath. It’s a winning combination. Durability I can’t tell you if it’ll still be going strong in ten years' time as I’ve only had it a month, but first impressions are spot on. It feels like a quality bit of kit that’s built to last.
Quality5
Comfort4
Value5
Jenny Stubbs
Customer Rated This 5 Stars 5/5
17 Jan 2026
The absolute best mattress I have ever slept on. My body likes a firm mattress as a stomach sleeper. I wake up without any aches. I can also not really notice my partner moving in bed. I was worried when it arrived rolled up in a box that I’d ordered something too thin and soft but I needn’t have been. I can not wait to get into bed again at night and am sleeping so well. When it is time to replace my teen son’s mattress, I’ll be replacing with one of these.
Value5
Quality5
Comfort5
Andrew Sinden
Customer Rated This 5 Stars 5/5
12 Dec 2025
We were after a very firm, orthopaedic mattress and the Rock Arthur is exactly that. Super firm and perfect for back sleepers who want a good nights sleep on a firm mattress. Delivery was also spot on. I’m disabled and couldn’t move the old or new mattresses. The delivery guys removed the old one and set up the new one for me - great service!
Comfort5
Value4
Quality5
Sarah Tomlinson
Customer Rated This 5 Stars 5/5
29 Jul 2025
This was the third mattress we ordered as we had issues with others. This was the cheapest out of them all, the easiest to get up two flights of stairs and the quickest delivery. Very comfortable too. We ordered the extra firm. We thought we would need toppers however I love the way it feels on my body. I would recommend.
Comfort5
Value5
Quality5
Durability5
Deborah Adams
Customer Rated This 5 Stars 5/5
07 Feb 2025
Only had the mattress for a week. I have it on a 60 day sleep trial. So far I am very impressed with it. It is extra firm., Its a heavy mattress which is a good sign. Anyway so far so good, I will know by the end of the sleep trial if its as good as I hope., maybe review it properly then
Value5
Comfort5
Quality5
Viewing 1 to 6 of 88
Our Promise

The Cool Rock Mattress has

A 60-night sleep trial Sleep on it at home — love it, or exchange it between nights 30 and 60.
A 96% keep rate Not a survey — our own order data, updated weekly.
A 1 year guarantee See exactly what's covered, and for how long.
Price Match Promise Seen it cheaper somewhere else? We'll match it.
·
Good To Know

Frequently asked questions

Can people with allergies use this mattress?
Absolutely, the Cool Rock mattress is an excellent choice for those who suffer from allergies. Its specific fillings and fabric contribute to a healthier sleep environment for individuals with sensitivities.
How does the pocket sprung support work?
The pocket sprung support is made up of individual springs that are each wrapped in fabric. This allows them to move independently, providing personalised support to your body. It also helps to minimise motion transfer, so you won't be disturbed if your partner moves during the night.
What materials are used in the mattress for temperature regulation?
The Cool Rock mattress includes body contouring gel foam that helps regulate body temperature, keeping you comfortable throughout the night.
What type of sleepers will benefit most from the Cool Rock mattress?
The Cool Rock mattress is ideally suited for front and back sleepers, as its firm sleeping surface provides the necessary support for these positions. This is particularly beneficial for individuals who prefer a firmer feel while sleeping, ensuring that their body is properly aligned throughout the night. Additionally, the combination of pocket springs and body contouring gel foam enhances comfort and support, making it a great choice for those who need a more robust mattress.
Is it necessary to flip this mattress on a regular basis?
This mattress is designed to be one-sided, so you don't need to flip it. However, it's a good idea to rotate it from head to toe now and then to maintain its shape and comfort.
What type of cover does the mattress have?
The Cool Rock mattress features a knitted cover that stretches with the mattress, providing great elasticity and breathability for added comfort.
How is the mattress finished for comfort?
The mattress has a micro quilted finish, which is created by stitching together the fabric and fillings, resulting in a patterned comfort quilt layer that enhances the overall feel.
Are there handles on the mattress for handling?
Yes, the Cool Rock mattress has handles attached to the border, which makes it easier to rotate and manage.
How long is the warranty period for this mattress?
The Cool Rock mattress includes a warranty of 10 years, ensuring you can be confident in its longevity and quality.
How does the firm surface of the Cool Rock mattress contribute to its comfort?
The firm surface of the Cool Rock mattress is designed to provide both support and comfort, making it especially suitable for front and back sleepers. Its combination of innovative gel foam layers allows for body contouring, which helps to distribute weight evenly and alleviate pressure points. Additionally, the mattress features a unique cooling effect, ensuring that you remain comfortable and temperate throughout the night.

60-night sleep trial: exchanges only, not refunds. Activated by purchasing a mattress protector at the point of order. Request your exchange between nights 30 and 60 of the trial; a £50 exchange fee applies. Full terms.

Keep rate: the share of this product's delivered orders in the last 6 months that were kept rather than returned. Updated weekly, rounded down, capped at 99%, and only shown where we have at least 30 delivered orders.

Recommendation rate: the percentage of verified Trustpilot reviews for this product with a rating of 4 stars or more, rounded down.

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