Nebula Cold Plunge Tub with Secure Lid, 360L

The Nebula N-CP is an inflatable cold plunge tub — round, black, freestanding — listed at £59.99 and rated 4.2 out of 5 from 48 ratings. It sits at number 9 in this guide, and the number it leads with is capacity: 360 litres. The same listing gives item dimensions of 25 x 12 x 64 centimetres, which multiply out to roughly 19 litres. Both figures are on the page, and they cannot both describe the same rigid tub. The 2.8 kg weight and the pole-and-drain setup suggest the dimension field is being used for something folded or packed, but the listing does not say that, and it is the only size information it gives.

A second set of figures does not line up either. The rating breakdown reads 69 five-star, 17 four-star and 14 one-star, which sums to 100 while the page reports 48 ratings in total — so those look like percentages, and read that way roughly one buyer in seven gave it one star. The spec table's "Included Components" field lists "Cold Plunge" and nothing else, while the bullet text promises a secure lid, a pump for the outer ring, a protective outdoor cover, a quick-start guide and a PVC repair kit. Everything on this page comes from Nebula's Amazon listing, not from any testing we have carried out.