size
XS: Chest circumference 30CM back length 20CM suitable for weight 0.5-1.5KG
S: Chest circumference 35CM back length 25CM suitable for weight 1.5-2.5KG
M: Chest circumference 40CM back length 30CM suitable for weight 2.5-4KG
L: Chest circumference 45CM back length 35CM suitable for weight 4-5.5KG
XL: Chest circumference 50CM back length 38CM suitable for weight 5.5-7.5KG