I own dumbbells that belonged to my father. It was made in cryolite factory in 1990 by my father and grandfather. It has simple forms: sleeve with thread and bagels, but there is no need to comlexity - it just works! Maximum weight of one dumbell is 23 killograms. I usually use it as 13 killograms.
I inherited it from my father. He used to do sport with them when he was young. It was bequeathed