Bonetto Cinturini 18mm Black Rubber Watch Strap Model 300L Imported Made in Italy from high quality, vanilla-scented vulcanized nitrile NBR rubber (not silicone). Will not attract lint or dust Nitrile rubber is waterproof, non-toxic and non-allergenic; resistant to salt and UVA rays Bonetto Cinturini produces OEM rubber dive straps for many of the world's most famous watchmakers Fitted with an 18mm brushed/satin stainless steel deployment clasp with push buttons and polished steel safety lock To determine your strap size, measure the distance (in millimeters) between the lugs of your watch