This is a pair of dumbbells, each pair weighing 10 kilograms each. Each pair consists of weights in sets of 3 kgs and 2 kgs.
Both the pairs, together weigh 20 kilograms. I must acknowledge that these are just the manufacturers description as I myself never tested the weights on a weighing machine to verify them. These are not metal. Only the handle and the axis of the dumbbell has a metal core.
<a href="https://en.wikipedia.org/wiki/User:Dajo767" class="extiw" title="en:User:Dajo767">User:Dajo767</a>
<span class="int-own-work" lang="">Own work by the original uploader</span>