Neck size 36cm - 47cm Size 2 is considered a medium size and should fit the following: Beagle, Bearded Collie, Border Collie, Cocker (English), Rough Collie, Saluki, Poodle, Bedlington Terrier, Brittany Spaniel, Hungarian Visla, Keeshond, Kerry Blue Terrier, Samoyed, Schnauzer, Scottish Terrier, Shar Pei, Welsh Terrier