Material: Polyester/elastomer/cotton, suitable for most European and American women's foot sizes (35-40). These durable, elastic invisible socks offer excellent elasticity and fit various foot sizes. The longer you wear them, the better they are for your feet, as they have a memory effect. They may feel tight the first time you put them on. Special design: Transparent silicone, non-slip socks keep you on your feet and respond to your voice. The perfect hem prevents them from slipping down, and the snug fit around the ankle is the second secret to solving sock problems. Cool and breathable – the socks have a breathable mesh design and contain antibacterial and deodorizing substances, making them a savior for sweaty feet and the perfect companion for your feet in summer. Special note: The socks will be very tight when you wear them for the first time, but they will loosen after you have worn them for a while, or they may loosen if you soak them for a period.