Please note that this product is a medical device and should only be used if advised by a healthcare professional. Before purchasing these stockings, you should first be properly measured by a healthcare professional and they should then recommend the correct size TED stockings for your particular needs. The manufacturer, Covidien, warn that fitting the wrong size of stocking may cause pain and a worsening of any condition. T.E.D.® Anti-Embolism Stockings have been clinically proven to reduce the risk of developing Deep Vein Thrombosis. They help to promote blood flow through compression. Size F-, REF 7594.