Please confirm that you buy Shin Guards from "Outfun" store. Other seller is selling this product without our permission.We can't guarantee the quality and your warranty if you buy from other seller. Designed with a lightwieght reinforced shell, Outfun soccer shin pad has high performance of impact resistant to help gaurd against the impact force of the soccer game. How to Select Your Size Measure Height or Shin Length from below kneecap to top of foot. If the information is unknow, use Age to determin size. Shin Length Shin Size 7 - 10 Inches = M is recommended Shin Size 10 - 12 Inches = L is recommended Player's Height: Size M - for child up to 4'6" tall Size L - for child or adult up to 5'4" tall Player's Age: Size M - for child 3 - 8 Years Size L - for child 6 - 14 Years Please see all images for sizing guides and product dimensions as well.