The Sporn® ID Collar™ lets you store your dog's contact details right inside the buckle. No need to purchase expensive and noisy tags for your dog. Simply use a permanent marker to write down your contact details on one of the three sheets of waterproof paper provided. Unlock the buckle, slide out the tray, place the paper inside the tray, then lock the buckle and you're all set! Still want to keep those noisy ID tags too? Not a problem! Attach them to the D-Ring on the ID Collar and use the paper tray as a backup, just in case the tags ever detach.