[Suitable for Small, Medium and Cats] The airtag dog collar is 21.3 inches in length, but with multiple holes in the strap, you can adjust it from 9-19.5 inches to fit your pet. We recommend you use it for cats, small and medium dogs. [How to Assemble] Measure around the base of your pet’s neck and place a finger between its neck and the tape. Cut excess tape to fit around pet’s neck. [Apple Airtag Compatible] Airtag dog and cat collars are fully compatible with Apple Airtags. By using this air tag clip collar, you can keep track of cats and dogs while they are hiding somewhere in the house. Never lose your pet with this small air tag dog/cat collar. [Comfortable and Durable] This airtag dog and cat collar is made of soft silicone, non-toxic, comfortable, sweat-proof, scratch-resistant and washable.H Weight 43g, easy to carry. Note that it is not suitable for small, skinny cats.