An Optional velcro strap in black or gray was supplied – these straps hooked up to the main male connection from the bracelet. Thankfully, the fabric strap with the IW3715-36 and also the alternate rubber strap from the IW3548 suit the Aquatimer! Christie’s This was mostly a ref. 6538 — https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/