An Optional velcro strap in black or grey was presented – these straps hooked up to the primary male link in the bracelet. Fortunately, The material strap within the IW3715-36 as well as the alternate rubber strap with the IW3548 match the Aquatimer! Nonetheless it is apparently the factor at https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/