The ZenCollar Premium Recovery Collar protects recovering animals (as well as shins, furniture and walls) so your animal can eat, sleep and play while still being protected. ZenCollar is an inflatable collar that is easy to blow up yourself. Thread your dog's collar through the openings and then pull the velcro strap. To find the right size, measure your dog's collar. Extra-small: approx. 7–15 cm Small: approx. 15–22.5 cm Medium: approx. 22.5–32.5 cm Large: approx. 32.5–40 cm Extra large: approx. 40–55 cm For larger breeds with long legs or noses or for animals that are in between sizes, always choose the bigger size. The outer cover is removable and can be washed if necessary