An Optional velcro strap in black or grey was provided – these straps hooked up to the very first male url on the bracelet. Luckily, the fabric strap within the IW3715-36 as well as the alternate rubber strap within the IW3548 match the Aquatimer! Christie’s This was largely a ref. https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/