Black Watch Replacement Band Genuine Calf Leather with Spring Bars and Deployment Butterfly Clasp 18mm Imported Argentina genuine leather. The more you wear, the softer it becomes.It also comes with a pair of spring bars. 316L medical stainless steel,allergy proof. It won't fade off. Sweatproof,,waterproof and also anti stink by using the first layer of leather to extend the life of the strap. Fine workmanship, ergonomic design,comfortable to wear. It gets thinner and thinner slightly from the head to the end, creating a 3-D effect and luxury feeling. It comes with varies sizes for you to choose from,covering most of the watch sizes,Timex, Casio, Seiko, Tissot, Citizen, U.S. Polo, Stuhrling, and Nautica,Breitling, Breguet, Cartier,Longines, Nomos, Omega,and other watches.