The size of a dog is measured on a withers.
Withers - a place on the spine between the shoulder blades four-legged friend.
Size S is suitable for dogs of the breed: Jack Russell, Mops, West Highland Wai, Welsh Corgi, Yorkshire Terrier, Dachshund, Chihuahua, Pikines, Dwarf Pinscher, Chinese Crested, Drever, Breton Basset, Papillon, Lhasa Apso, Maltese Bologna, Spitz Pomeranian.
Size M is suitable for dogs of the breed: French Bulldog, Beagle, English Cocker Spaniel, Barbett, Boxer, Shelty, Labaradoodle, Russian Spaniel, Poodle, Welsh Terrier, Eskimo Spitz.
Size L is suitable for dogs of the breed: Border collie, Moody, Australian shepherd dog.