Tagvault Pet. It's waterproof, fits every collar, and is very comfortable. ElevationLab created an AirTag case that takes the abuse of an active full-size dog and also fits really well on a cat. This AirTag case works with all pet collars, it is super durable and it's a set and forget kind of installation. Note from Macfixit staff: We have been using these with our pets and we're super happy with these pet collar cases. Our boss' Spoodle swims with one on her collar and it really is waterproof. They are super easy to install, they really are set and forget and they work perfectly well with the Apple Find My app. While we never had an emergency yet, we've tested these extensively and are confident these will work well if a need arises to find a lost dog or a cat. This is great product and it has our 100% recommendation. Perfect way to keep track of a missing pet, great for a cat or a dog. Features Comfortable & secure AirTag mount for pets. Doesn't dangle. Waterproof, dogs can swim with it. Durable composite construction + CNC machined stainless hardware. Works with any width collar or harness. Works with collar thicknesses all the way up to 0.20"/5mm (Which is about 99% of collars. Some doubled up leather or studded collars are too thick). Fits dogs and cats over about 10lbs/4.5kgs. (Smaller than that, it's pretty big on the neck, but still works). Front screws let you change the AirTag battery without taking it off the collar. Signal & sound passes through. Patent pending thru-collar mount uses custom piercing self-tapping screws that are easy to install with our supplied Torx driver. NOTE: Collar and AirTag are not included and for illustrative purposes only. Simply install on your favourite collar with the screwdriver that is provided in the packaging. Apple AirTag is not included.