RelaxSan open-toe support knee high socks with firm graduated compression of 20-30 mmHg. Ideal for people suffering from poor blood circulation, varicose veins, phlebitis, oedemas, and chronic venous insufficiency. These open-toe support knee highs are also Ideal to prevent thrombosis after surgery. They feature reinforced heels for maximum comfort and durability and soft elastic top bands, which do not squeeze your calves. Fabric content: 76% nylon, 24% elastane<br> <br> <b>Size guide:<br> <br> Size 1: Ankle Girt: 7-8 in<br><br> Size 2: Ankle Girt: 8-9 in<br><br> Size 3: Ankle Girt: 9-10 in<br><br> Size 4: Ankle Girt: 10-11 in<br><br> Size 5: Ankle Girt: 11-12 in<br><br></b>