Doubleslee Memory Foam Mattress (5FT King) – Medium Firm, Gel Memory Foam & Support Layer, in a Box (150x200x15cm)

If you like the idea of memory foam but you don’t want to feel stuck in it, the Doubleslee gel memory foam mattress is built around that “pressure relief with a cooler feel” concept. It’s an all-foam, dual-layer design: a softer gel memory foam comfort layer on top, and a denser support layer underneath to keep your body supported through the night.

That said, it’s still memory foam—so while it’s designed to feel more breathable and sleep-cooler than plain foam, it may not suit everyone who wants a very bouncy or very firm surface.

What it is and what it’s for

This is a king-size (5FT) memory foam mattress delivered in a box, using a dual-layer all-foam approach. The comfort side is described as a gentle gel memory foam layer that moulds to the body and contours, with the aim of reducing pressure points. In practice, this tends to suit people who sleep on their side or who want a bit more “sink-in” around shoulders and hips.

Underneath sits an 11cm high-density foam support layer. Based on the description, the goal here is even support and a more stable “bedrock” feel rather than a mattress that collapses too easily.

Where it stands out

The most distinctive part, on paper, is the gel memory foam layer. It’s positioned as a comfort upgrade that should help with pressure relief and a more relaxed sensation, without ignoring temperature as much as some traditional memory foam options.

You also get a hypoallergenic angle: the cover fabric is described as hypoallergenic with breathable holes. If you tend to sleep hot, or you’re simply trying to create a cleaner-feeling sleeping environment, this is the sort of feature set worth paying attention to.

And yes, the “in a box” delivery matters too. The mattress is vacuum-sealed and compressed for transport, then needs time to expand.

What you’ll notice day to day

A mattress like this usually delivers a mix of “hug” and “support”. With gel memory foam, you can expect a comfort layer that contours to your body shape rather than sitting only on top. Meanwhile, the high-density support layer is meant to keep the sleeping surface feeling more controlled—helpful if you share the bed or you want less wobble.

There’s also a stated focus on breathability and shock absorption. That’s not the same thing as saying it will be instantly breathable in every room, but it does suggest the mattress is designed to cope better with everyday temperature and humidity.

One practical note: after unboxing, you should allow 48–72 hours for the mattress to fully expand. If you’re hoping it’s ready the same day, you may be disappointed.

Durability and the reality check

Doubleslee claims the mattress is carefully designed for durability and long life, stating it should retain its original shape and supportive properties even with frequent use. They also mention a free replacement service if you run into a problem during use, such as the mattress being stepped on and collapsing.

That sounds reassuring, but it’s still wise to treat “memory foam durability” as a mix of design plus how you use it. If your base is unsuitable or you routinely put unusual loads on the mattress, any mattress can suffer.

Who it suits best (and who should skip it)

It’s a good fit if you want a memory foam mattress with a gel comfort layer aimed at reducing pressure points, and you prefer the feel of a mattress that contours rather than one that stays rigid.

It makes sense if you’re looking for an in-a-box solution—especially if you need easier transport or a simpler setup process than traditional delivery.

It might not suit you if you’re after a very firm, fast-response feel. Memory foam is often more about cushioning and moulding than springy support, so if you dislike that sensation, this could feel a bit too “soft and embracing”, even though the mattress is described as medium firm.

Tech summary (the bits you can actually use)

The mattress is described as an all-foam, dual-layer setup with a gel memory foam layer on top and a high-density foam support layer underneath. The pack format is vacuum-sealed and compressed, then expanded after unboxing.

As provided, the size is 150x200x15cm.

Mini FAQ: common buying questions

How long does it take to expand after opening the box?

The instructions say you should allow 48–72 hours for the mattress to fully expand.

Does it include a gel layer for cooler sleep?

Yes—there is a gentle gel memory foam layer on top, positioned as a way to reduce pressure points and support a cooler, more comfortable sleep.

Is it hypoallergenic?

The fabric is described as hypoallergenic and includes breathable holes.

Is it medium firm, or closer to soft?

It’s described as medium firm. Still, because it’s memory foam, feel can lean more cushioned than an “everyday firm” spring mattress depending on your body weight and sleep position.

Final verdict

It’s a solid pick if you’re buying for pressure relief and comfort, and you like the idea of a gel memory foam comfort layer backed by a dense support layer—plus you need an in-a-box mattress that’s easier to transport. If you prioritise a very traditional springy feel or you can’t stand any memory-foam moulding, you may want to skip it, because memory foam always comes with some degree of contouring, even at medium firmness.