The Jay-Be Graffiti Art e-Pocket Mattress is a thin pocket-sprung mattress for a top bunk, and that's the one job I'd give it. At 14cm it sits low enough for most bunk guard rails, which is the right priority up there. On a single bed or a lower bunk it's too thin, and one owner who put it on a mid sleeper could feel the slats through it.
Thin on purpose
It's a single layer of e-Pocket springs under fibre comfort layers and a knitted graffiti-print cover. No foam goes into it, it has one sleeping side, and Jay-Be sizes it to suit Bensons' bunk beds.
On a top bunk, thin is good. The mattress has to sit below the maximum depth marked on the bed so the guard rail still stops a child rolling out, and a deeper mattress eats into that height. One owner was talked into it for a mid sleeper and was disappointed it didn't come up higher. On a raised bed, though, the low height is what keeps the rail doing its job for your child.
Short, soft or slats: the complaints worth reading
The owner reviews here are the most mixed in the range. The complaints about the mattress itself are a short length, one owner finding it too soft, and one feeling the slats through it. Others are about the wrong mattress being delivered and about customer service, which are the retailer's problems, though no less annoying for it.
The length complaint is the one I'd act on. Measure your mattress once it's fully expanded, and return it if there's a gap, because a child's mattress should fit the frame exactly. For the slats, check the gaps on the bunk: anything more than about 7cm apart will show through a mattress this thin.
Not for a single bed or an older child
Avoid it for a single bed your child uses every night, or a lower bunk with no depth limit, where a deeper mattress gives more support. Avoid it if your child is older or heavier. And skip the Graffiti Art e-Sprung, the open coil version of this mattress, which I wouldn't put under a child at all.
What to buy instead
If your bunk's limit allows 16cm, the Graffiti Art Deep e-Pocket puts a deeper spring core under the same print. For a single bed, buy the Jay-Be Dual Support e-Pocket, which has two layers of pocket springs at 20cm. Measure whichever you choose when it arrives.