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.
- 75cm each for two people sharing: That's 75cm each of firm, supportive surface, so you can both settle into your own space rather than meeting in the middle.
- Less disturbance on different schedules: If one of you gets up hours before the other, the wider gap between sleepers on a UK king means an early alarm is less likely to wake your partner.
- 200cm of length for taller sleepers: The UK king is 10cm longer than the UK double, which means anyone approaching six foot can stretch out on a firm surface without their feet hanging off.
- Firm support that suits a shared bed: The PostureTech Core Support Springs vary their tension across the mattress, so a heavier partner and a lighter one each get support matched to where they press.
- Room for pregnancy pillows and position changes: During pregnancy and the months after, the extra 15cm of width over a UK double leaves space for propping pillows without crowding your partner.
This size suits you if...
You share the bed every night and have outgrown the width of a double, you or your partner keep different hours and want early starts to go unnoticed, or one of you is approaching six foot and needs the 200cm length. It also suits couples who like a firm feel and want space to sleep apart from each other's movement rather than a mattress that absorbs it.
Consider another size if...
Your bedroom falls short of our suggested minimum of 2.7m x 2.9m, or you mostly sleep alone. We'd recommend the UK double instead, which needs at least 2.6m x 2.8m of floor space.
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Is the Sealy Harlow Ortho Plus in a UK king big enough for a couple?
Yes, comfortably for most. At 150 x 200cm you get 75cm each for two people sharing, which is the width most couples find enough to sleep without disturbing each other. On a firm orthopaedic mattress like this, that space does the isolation work: the further apart you sleep, the less you feel a partner turning over.
Will the UK king suit us if my partner is over six foot?
Length is often the reason to choose it. The UK king is 10cm longer than the UK double at 200cm, so a sleeper around or over six foot gets clearance for their feet. The firm surface also makes it easier to shift position without sinking, which taller back and front sleepers tend to prefer.
What room size does a UK king Sealy Harlow Ortho Plus need?
We suggest at least 2.7m x 2.9m, with 3.2m x 3.2m feeling comfortable once wardrobes and bedside tables go in. New build master bedrooms can be tighter than they first appear, so measure with your existing furniture in mind. If the room won't stretch to it, the UK double needs at least 2.6m x 2.8m.
Should we choose the UK king or the UK super king in this mattress?
The UK super king is 30cm wider than the UK king, and both are the same 200cm length. If you share with a dog that claims its share of the bed, or you simply want maximum space, the extra width helps, but you'd need a room of at least 3m x 2.9m. For most couples the UK king is the practical choice.
Does a firm mattress reduce partner disturbance in a king size?
It helps in this size. The Harlow Ortho Plus has a firm feel with springs that respond most where your body presses, so movement stays fairly local rather than rolling across the bed. Combined with 75cm each for two people sharing, one of you getting up early is far less noticeable than it would be on a double.