The size number corresponds to the child's length/height in centimetres. Some brands manufacture their clothing in dual sizes and they are also included within this range. The age next to it is an approximate guide and it's best to quickly measure your child and go for the nearest bigger size for maximum comfort and wear.
FRED's WORLD by GREEN COTTON organic cotton top FOX
JNY colourful kids organic cotton zipsuit SUBMARINE
MOROMINI organic cotton baby leggings FLOWER POWER