Snap button closure. Label at back. Size 00 : Mini breeds - Chihuahua, Yorkshire,Length: 25cm,Neck: 22cm,Chest: 32cm,Weight: 1.5-2kg. Size 0 : X-small breeds - Maltese, Toy Dachshund,Length: 30cm,Neck: 26cm,Chest: 40cm,Weight: 2.5-3kg. Size 1 : Small breeds - Jack Russel, Dachshund,Length: 35cm,Neck: 30cm,Chest: 45cm,Weight: 5-7kg