Protective collar for injuries, rashes and post-surgery procedures. Does not inhibit the animal's field of vision. XSmall: Outer diameter 16cm, inner diametier 5cm. Suitable for Yorkshire terrier, papillion etc. Medium: Outer diameter 25.5cm, inner diameter 11cm. Suitable for spaniel, poodle etc. Large:  Outer diameter 30.5cm, inner diameter 16cm. Suitable for retriever, border collie, German shepherd etc. XLarge:   Outer diameter 36cm, inner diameter 18cm. Suitable for curly coated retriever, howawart, rhodesian ridgeback etc. XXLarge:  Outer diameter 44cm, inner diameter 22cm. Suitable for rottweiller, great dane, mastiff etc.