An Optional velcro strap in black or gray was presented – these straps attached to the very first male website link with the bracelet. Thankfully, The material strap within the IW3715-36 and the alternate rubber strap from the IW3548 in shape the Aquatimer! Christie’s This was mostly a ref. 6538 https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/