Sealy Harlow Ortho Plus Mattress
Mattress
Sealy Harlow Ortho Plus Mattress
Size
Firmness
Firm
Construction
Depth (cm)
26
Layers
2
Layer Details
- Comfort Layer. Soft white fibre fillings sit at the surface to cushion the hardest parts of the body, which means your hips and shoulders get a little give before reaching the firmer support below. It's a traditional filling with a slightly springier feel than foam.
- Support System. PostureTech Core Support Springs use unique shapes and varied tension across the mattress, which means fuller support where your body presses hardest and pressure relief where it doesn't. This is the layer doing most of the orthopaedic work.
Layer details from mattressonline.co.uk product page, September 2026.
- 90cm each for two sharing: With 90cm each for two people sharing, a restless partner rolling over on this firm surface happens far enough away that you barely register it.
- Firm support across the full width: The PostureTech Core Support Springs vary their tension across the mattress, which means each sleeper gets support matched to where their body presses, even 180cm apart.
- Room for the whole household: When children or a large dog treat your bed as theirs, the extra 30cm over the UK king keeps a share for everyone.
- A firm feel that keeps you on top: Soft white fibre fillings over firm springs give a traditional, slightly springy surface rather than a sinking one, so moving around this much mattress stays easy.
- No flipping, which helps at this size: It's single-sided, and at 180 x 200cm that's a genuine plus, because flipping a mattress this large is a two-person job you never need to do.
This size suits you if...
You share the bed every night and want the maximum sleeping space a standard UK size offers, your partner is restless enough that distance matters more than any comfort layer, or children and pets regularly join you and a UK king no longer leaves everyone a fair share. It also suits a large master bedroom where a smaller bed would look lost, provided you both like a firm feel.
Consider another size if...
Your bedroom is under our suggested minimum of 3m x 2.9m, or you sleep alone. We'd recommend the UK king instead: it's 30cm narrower, the same length, and we suggest at least 2.7m x 2.9m for it.
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Will a super king Sealy Harlow Ortho Plus fit in my bedroom?
We suggest a room of at least 3m x 2.9m for a UK super king, and that's a genuine minimum: you'll want space to walk around both sides and open wardrobe doors. If your room falls short, the UK king is 30cm narrower and the same length, and we suggest at least 2.7m x 2.9m for that size.
Is the Sealy Harlow Ortho Plus super king good for restless couples?
Yes, and largely because of the space. With 90cm each for two people sharing, movement on the other side happens a long way from you. The firm feel helps too: the surface doesn't cradle you in one spot, so shifting position is easy without disturbing your partner. Some owner reviews mention edge support as a weak point, so sit centrally where possible.
Can I get the Harlow Ortho Plus super king up the stairs?
This is the check that bites at 180 x 200cm. Measure your staircase, any landing turns and the bedroom door swing before ordering, because a mattress this wide has far less give around tight corners than a UK double. Sealy doesn't publish a weight for this mattress, so check the retailer's own guidance if access is tight.
Is a super king worth it over a king for the Harlow Ortho Plus?
If children wander in at night or a dog shares the bed as routine, yes. The UK super king is 30cm wider than the UK king at the same length, and that extra width is the difference between everyone keeping a share and someone clinging to the edge. If it's just the two of you and neither is restless, the UK king may be plenty.
How firm does the Harlow Ortho Plus feel in a super king?
The firmness is the same in every size: a firm orthopaedic feel with soft white fibre fillings giving a little cushioning over the springs. What changes in the UK super king is how you use it. With 90cm each, you can spread out on your back or front, the positions this firm build suits best, without crowding anyone.