Old Bones Therapy DRIP LETTERS SKULL "Combo Pack" Compression Socks are designed to improve performance and speed up muscle recovery through graduated compression, which increases blood flow allowing you to perform at your peak. Our advanced design includes foot and arch supports, as well as extra cushion in all the right places for extra stability and protection. These compression socks are built to last using a blended 75% nylon and 25% lycra knitting thread at a graduated 15-20 mmHg compression level. These socks are also great for anyone who spends a lot of time on their feet, like nurses, police, firefighters, construction workers and are great for travel.