Harrison Spinks Knaresborough 3750 Pocket Ortho Mattress
The Harrison Spinks Knaresborough 3750 is a firm pocket spring mattress whose springs move independently, which means less motion transfer when a partner shifts in the night.
- Firm feel for back & front sleepers
- Helps keep your spine aligned
- Sizes up to Emperor
£744
Get the lowest price we've found
The Knaresborough 3750 comes in five sizes, from UK Single right up to UK Emperor, which is rarer than it should be. It's listed with Mattress Online, where the range is stated as exclusive, and carries a retailer-listed 5 Year Guarantee. If you want a properly firm feel from a pocket spring build, it's worth a look.
Mattress specifications
Firmness
Firm
Type
Pocket Spring
Depth (cm)
24
Number of Layers
2
Trial Period (nights)
100
Warranty (years)
5
Price Range
£744 to £1,644
Best Sleeping Position(s)
Back Sleeping
Stomach Sleeping
Certifications
BS 7177
Assessed from the specification published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
Why should you choose this mattress?
The main draw here is a genuinely firm pocket spring feel, which suits back and front sleepers who like a supportive, no-sink surface. If you've found softer hybrids leave you feeling swallowed up, a firm ortho-style pocket spring mattress like this tends to keep your spine in a more neutral line. The size range is another quiet strength: Emperor options are hard to find, so couples wanting serious width have a real choice here. Mattress Online lists a 5 Year Guarantee and a 4.5 customer rating. It isn't a budget buy, though pocket spring construction at this firmness generally justifies the step up.
Key features & layer details
Comfort fillings
Wool, cotton, hemp and soft white fibres, finished with tufted layers, give natural insulation and help regulate temperature. For you, that means a breathable, foam-free top that should feel less clammy than a dense synthetic surface.
Support system
3750 individual pocket springs sit in cloth pockets, so each spring works on its own. This gives more tailored support to each part of your body, with the firm, no-sink feel the mattress is known for.
Layer details from mattressonline.co.uk product page, October 2026.
Best suited for?
Back sleepers
The firm pocket spring feel gives a supportive, no-sink surface, which suits anyone who likes to stay level on top of the mattress.
Front sleepers
A firm ortho-style build keeps your midsection from dipping into the surface, which helps if you sleep face down and want to stay flat.
Couples
Five sizes run from UK Single up to UK Emperor, so partners who want serious width have a rare choice of very large options.
Heavier sleepers
Firm pocket springs in a 24cm depth give a supportive, no-sink feel, which suits heavier bodies that tend to press deep into softer hybrids.
This is a firm mattress, so lightweight side sleepers may find it a little too unyielding at the shoulder and hip. If you prefer a plush, cushioned surface, or want the slow-sink feel of memory foam, look elsewhere.
Save on an earlier or ex-display model
Some retailers still sell the earlier version of this mattress, or ex-display and returned stock at a lower price. These are the sizes where it costs less than the current model's best price.
Harrison Spinks Knaresborough 3750 Pocket Ortho Mattress
Last seen for £749 at Mattress Online on 5th November 2026
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FAQ's
How firm is the Harrison Spinks Knaresborough 3750?
It's listed as firm. That means a supportive surface with limited give, which tends to suit back and front sleepers, although lightweight side sleepers may find it slightly too solid for comfortable pressure relief at the shoulder.
What sizes does the Knaresborough 3750 come in?
Five UK sizes: Single, Double, King, Super King and Emperor. The Emperor option is a genuinely useful inclusion, as many mattresses stop at Super King.
How much does the Harrison Spinks Knaresborough 3750 cost?
It depends on the size you choose, and the price table on this page shows the current price for each size.
Does the Knaresborough 3750 come with a guarantee?
The retailer listing includes a 5 Year Guarantee. Check the retailer's terms for exactly what it covers before you buy.
Where can I buy the Knaresborough 3750 mattress?
The price table on this page shows the current prices. It's available from Mattress Online, where the range is stated as exclusive. There's no product page for it on the Harrison Spinks website, so you won't find it sold directly by the brand.
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