S: Weigh less than 7 kg, with a chest circumference of 28-38cm and a neck circumference of 20-25cm
M: Weigh less than 10 Kg, with a chest circumference of 38-45cm and a neck circumference of 25-30cm
L: Weigh less than 15 Kg, with a chest circumference of 45-50cm and a neck circumference of 28-33cm
XL: Weigh less than 22 Kg, with a chest circumference of 52-57 cm and a neck circumference of 31-38 cm