Bow ties has hook and because of it you could use it as a collar.
Sizes:
Size Small – 21 – 26cm
Size Medium – 26 – 31cm
Size Large – 31 – 36cm
Size Extra Large XL – 36 – 41cm
Size Extra Extra Large XXL – 41 – 51cm
If you are not sure about the size, we recommend to buy a littlebit bigger and regulate it to smaller size.