The recommended age does not necessarily apply to everyone.
The fit varies depending on the height, weight, and body type of the child
S (1-2y) : width of the body is 16cm (single line measurement when relaxed, stretches 2cm both ways), total length is 51cm
M (3-4y) : width of the body is18 cm, total length is 64cm
L (5-6y) : width of the body is 20cm, total length is70.5 cm