No Show Invisible: Easy to match different kinds of shoes, such as sneakers, oxford, running shoes, casual shoes, training shoes, athletic sports shoes, and business shoes., not for very low cut shoes. Three Size: S: US Women Size 5-8, Men Size 3-5 / M: US Women Size 8.5-13, Men Size 5-7 / L: US Women Size 13-15.5, Men Size 8-10 Best Gift choice: No show socks for women and men. It's a great gift for mother, teacher, wife, daughter, sister and friends. Easy to wash: machine wash or hand wash,do not bleach