An Optional velcro strap in black or gray was made available – these straps hooked up to the primary male connection from the bracelet. Luckily for us, the fabric strap through the IW3715-36 and also the alternate rubber strap from your IW3548 suit the Aquatimer! If the Rolex Submariner ref. https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/