An Optional velcro strap in black or gray was offered – these straps hooked up to the main male link of the bracelet. The good thing is, The material strap from the IW3715-36 plus the alternate rubber strap from the IW3548 match the Aquatimer! Once the Rolex Submariner ref. 116610LN https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/