Firmness
Medium Soft
Type
Pocket Spring
Depth (cm)
28
Number of Layers
5
Trial Period (nights)
100
Warranty (years)
5
Price Range
£1,324 to £1,824
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 the spring-on-spring construction. Rather than foam comfort layers, you get tiers of mini pocket springs above and below a Cortec Quad support core, which means a bouncier, more breathable feel than memory foam offers, with heat and moisture able to escape. If you're a hot sleeper, that airflow is a genuine advantage. The soft to medium tension gives noticeable cushioning at the shoulders and hips, a good match for side sleepers and lighter builds. Yes, £1,324 is a serious spend, but you're paying for a handcrafted, chemical treatment-free, 100% recyclable mattress from a National Bed Federation approved brand. Mattress Online lists a 100-night trial, which gives you time to be sure.
Key Features & what's inside
- Comfort Layer. Soft White Fibres, a synthetic filling, create the cosy top feel. They're durable and resilient, so the layer holds its shape over time rather than flattening quickly.
- Mini Pocket Springs (Top). Two layers of springs, 4000 HD and 2500 HD, sit near the surface. They give a bouncy feel and improve airflow, which means less heat building up around you overnight.
- Mini Pocket Springs (Additional). A layer of 1000 Posturfil mini pocket springs adds further cushioning. It also helps dispel moisture and heat, keeping the sleep surface fresher.
- Support Core. 1000 Advanced Cortec Quad pocket springs form the main support unit, each encased in its own fabric pocket. That means the springs respond to your body individually, supporting spinal alignment rather than pushing back as one block.
- Mini Pocket Springs (Bottom). Further layers of mini pocket springs sit beneath the core. They add a little extra give and keep air moving through the whole mattress.
Layer details from mattressonline.co.uk product page, September 2026.
Who's it NOT for?
This isn't the mattress for you if you prefer a firm surface: the soft to medium tension is deliberately gentle, and heavier back or front sleepers may sink further than is comfortable. Couples sensitive to a partner's movement should also be cautious, as some owners report noticeable motion transfer. Smaller sizes aren't listed, only King and Super King.
Harrison Spinks Quilted Fusion 12000 Pocket Mattress
How firm is the Harrison Spinks Quilted Fusion 12000?
It's described as soft to medium. That gentler tension suits side sleepers and lighter builds, who'll feel cushioning at the shoulders and hips, although heavier sleepers or those who like a firm surface may find it a little too yielding.
Does the Quilted Fusion 12000 come with a trial period?
Mattress Online lists a 100-night trial with this mattress. That trial is the retailer's own offer rather than a Harrison Spinks guarantee, so if you buy elsewhere, check that retailer's terms before ordering.
Is the Harrison Spinks Quilted Fusion 12000 good for hot sleepers?
It should be a sensible pick. The construction is springs rather than foam, with mini pocket spring layers designed to promote airflow and dispel heat and moisture, which means less warmth trapped around you than a foam-topped mattress typically allows.
What guarantee does the Quilted Fusion 12000 have?
The mattressonline.co.uk listing states a 5 year guarantee. As this appears on a retailer's page rather than the brand's own site, confirm the guarantee terms with whichever retailer you buy from.
What sizes is the Quilted Fusion 12000 available in?
It's listed in UK King and UK Super King, priced from £1,324 to £1,824. No Single or standard Double is listed, so if you need a smaller size you'll want to consider a different model.
Couldn't find an answer to your question? Send us a message