HDT Bonetto Cinturini Rubber Material Divers Strap Model 286 [24mm] Rubber strap with 3 dimensional pattern to match with many elegant to sporty watches. Genuine Rubber does not contain any silicon. Will last you years without becoming brittle or forming cracks, unlike silicon. Made by Rubber Strap manufacturer in Italy who supplies to many well known Swiss Watch Manufacturers. NBR 217 Vulcanized Rubber  Anti-allergic and non-toxic