An Optional velcro strap in black or gray was made available – these straps attached to the very first male link of your bracelet. The good news is, The material strap from your IW3715-36 plus the alternate rubber strap from the IW3548 in good shape the Aquatimer! About Superwatchman Superwatchman.com https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/