This bodysuit is 100% cotton Short sleeve and nice for baby0-3 months:recommended height 21.5-24 inches3-6 months:recommended height 24-26.5 inches6-9 months:recommended height 26.5-28.5 inches9-12 months:recommended height 28.5-30.5 inchesPlease allow 0.5-1 inches error due to manual measurementDurable and environmentally friendly material