Firmness
Extra Firm
Type
Orthopaedic
Depth (cm)
27
Number of Layers
3
Trial Period (nights)
Warranty (years)
1
Price Range
£239 to £439
Best Sleeping Position(s)
Certifications
Assessed from Spring King's published specification for this mattress, captured September 2026, and from regular price comparison across our UK retail partners.
Choose the Ruby Ortho if you actively want an extra firm feel. That is a smaller group than the marketing for orthopaedic mattresses sometimes suggests, but if you sleep on your back or front, or you have simply always preferred a hard bed, this delivers it at a modest price. The continuous coil lattice spreads support across the whole surface, which means less of a sinking feeling when you change position. The Belgian damask cover is breathable, helpful if you tend to sleep warm, and the mattress is hypoallergenic and fire resistant to the BS7177: 2008 domestic standard. Delivery is free next day to mainland UK, though some addresses may incur a small fee. The guarantee is one year, which is short.
Key Features & what's inside
- Cover. A breathable Belgian damask fabric cover. The breathability helps air move away from your body, which means you are less likely to overheat.
- Comfort Fillings. Soft white fibre fillings made from 100% polyester. These add a little softness over the springs, though the overall feel remains extra firm.
- Support System. A traditional open coil unit built from one continuous high tensile spring formed into a lattice. This spreads support evenly across the mattress, which means a stable, uniformly firm surface underneath you.
Layer details from mattressnextday.co.uk product page, September 2026.
Who's it NOT for?
Side sleepers, especially lighter ones, will probably find it too hard on the shoulders and hips. Anyone who prefers a contouring, pressure-relieving feel should look at pocket sprung or foam hybrid options instead. Couples wanting minimal motion transfer may also struggle, as open coil units tend to move as one.
Spring King Ruby Ortho Extra Firm Mattress
Across 115 reviews on the MattressNextDay product page, the Ruby Ortho holds a 4.8 rating, with owners praising the comfort, support and quality of materials. Some found it firmer than expected, which several felt worked in favour of their spinal alignment.
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How firm is the Spring King Ruby Ortho mattress?
It is rated Extra Firm, the hardest end of the firmness scale. That suits back and front sleepers who want minimal sink, but it is a genuinely hard feel, so if you have never slept on an extra firm bed before, expect a noticeable adjustment period.
How deep is the Spring King Ruby Ortho Extra Firm?
It measures 27cm deep, so standard fitted sheets should fit without trouble.
What sizes does the Spring King Ruby Ortho come in?
Five UK sizes: Single, Small Double, Double, King and Super King, with prices ranging from £239 to £439.
Does the Spring King Ruby Ortho have a guarantee?
Yes, it comes with a one year guarantee. That is shorter than many brands offer, so factor it into your decision if long-term cover matters to you.
Is the Spring King Ruby Ortho hypoallergenic?
Yes, it is certified hypoallergenic, and it meets the BS7177: 2008 fire resistance standard for domestic use, classed as low hazard.
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