THE Original Dog Door Bell! Superior design with six large, loud bells and an adjustable length strap. Not only is our Potty Bell the best in function, it also stands out with our unique attractive design. Our Potty Bell construction allows you to hang it on a lever-style door handle, a traditional door knob or a patio/sliding glass door handle! Other bells don't allow for their strap to pass through the sliding door handles due to their poor bell placement. Our bells have been placed on our strap for maximum sound capability PLUS easily hangs on ALL types of door handles/levers and knobs! There is absolutely no skimping on the quality of our bells...EVER! Be sure to look closely at the heavy weave we use for our Potty Bell straps! We set ourselves apart from the competition with our quality, hands down. Cheaper bells will be destroyed quickly with dogs' paws and claws, but Potty Bells will last for years! That's why we have a lifetime warranty. Our thousands of customer reviews speak for our unsurpassed Potty Bell quality. Don't expect to pay less for a better dog doorbell...it doesn't exist.