Firmness
Firm
Type
Pocket Spring
Depth (cm)
24
Number of Layers
2
Trial Period (nights)
100
Warranty (years)
5
Price Range
£648 to £1,388
Best Sleeping Position(s)
Certifications
Assessed from the specification published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
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. Yes, availability is limited to one retailer, but that retailer lists a 5 Year Guarantee and a 4.5 customer rating. At £648 for a Single, it isn't a budget buy, though pocket spring construction at this firmness generally justifies the step up.
Key Features & what's inside
Awaiting up to date specifications. Please check back later.
Who's it NOT for?
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. Anyone wanting to compare prices across shops will also be limited, as it's listed with one retailer.
Harrison Spinks Knaresborough 3750 Pocket Ortho Mattress
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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?
Prices range from £648 to £1,388 depending on the size you choose, starting at £648.00.
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?
It's currently available from one retailer, 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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