An Optional velcro strap in black or grey was presented – these straps attached to the initial male link with the bracelet. Fortunately, The material strap through the IW3715-36 as well as alternate rubber strap within the IW3548 in good shape the Aquatimer! Christie’s This was mostly a ref. 6538 https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/