Please choose boxers from the Green Mouse Store not others. Size:1-3T(S/Height 35.5-43 in),3-5T(M/Height 40-46 in),5-7T(L/Height 41-49 in),6-8T(XL/Height 47-52 in),8-9T(XXL/Height 51-58 in),9-11T(XXXL/Height 57-62 in),please choose the right size by your height. Notice the washing label is on the outside of the underwear. Breathable: this product is made from high-quality breathable material, effectively keeping the skin and intimate part clean and comfortable. Comfy Elastic Waist: the little boy underpants are designed with elastic waistband, which offers enough comfort.