One Size Fits All
The Whistle 3 only comes in one size but is designed for any pet over 8 lbs. Works great for smaller dogs and cats too!
Unlike other competitors (in which the product is the collar itself), Whistle 3 was designed specifically so that you can keep using your own collar. :)
Whistle 3 comes with an attachment piece to secure the device directly onto your pet’s existing collar or harness (up to 1" wide). The device can easily be removed from the attachment when it needs to be charged.