This combination does not exist.
SIZE CHART:
Size 2 ( Small ) neck: 24-26cm head: 24cm( Cats and Toy Breed Dogs )
Size 3 ( Medium ) neck: 26-30cm head:29cm( Fits Medium sizes dogs )
Size 4 ( Large ) neck: 30-40cm head:34cm( Fits larger breed digs like Labradors )
