1. [adjustable tightness] Baby Knee Pads for Crawling.Velcro, adjustable in size, suitable for children aged 1-4. Children can also ride bicycles as protection.2.[mesh breathable] 100% polyester fiber, breathable mesh, more comfortable to wear, not muggy in summer3. [sponge pad] thicken the sponge pad to protect the knee and prevent damage caused by friction.4. can better protect babies who learn to crawl.Adjustable Knee Pads Leg Warmers,Safety Protective Cover,Soft Protector with Elastic Sponge for Toddlers, Infants, Baby Boys, Girls, Kids5. [football design] football design allows children to enjoy playing while crawling.