This is a rubber spearfishing weight-belt from Ocean Hunter with a classically reliable Marseille release mechanism. The rubber construction is super durable and is constructed for a long life.
Rubber weight belts have the advantage that they stop the problem of your weight shifting, which happens on descent because of the compressing wetsuit.
The Ocean Hunter Marseille Weight Belt consists of a 50mm wide belt and a reliable stainless buckle. It is one of the top choices for many professional freedivers and spearos.