Easy to Clean - hand wash these heel cups with warm water and soap. Do not dry under the sun. Do not machine wash. Do not tumble dry. Add baby powder if the sleeves become slippery. Anti-slip and Breathable - each heel sleeve has holes to provide air circulation and reduce sweating. Stretchable silicone gel keeps the cup inserts in place during walking, running, long-time standing or intense exercise. Absorb Shock - high grade thick silicone provides cushion and alleviates symptoms of Achilles tendonitis as well as reduces discomfort caused by swollen ankles or bruised feet. Easy to Put On and Wear - slip each heel brace on your foot and feel fast pain relief from bone spurs or cracked and sore skin caused by blisters. Comfortably wear them all day without or under socks with any shoes (even dr marten boots). One Size Fits Most - Silicone Heel Protectors - these soft gel cushion ankle cups fit men and women feet with shoe sizes ranging from UK 3-12 (EU 35.5-47). Can be worn on either left or right foot.