Jobst Vairox Knee High Stockings with Zipper, 30-40 mmHg will create extra firm compression to help with severe conditions such advanced vein vairicosities, severe and lymphatic edema, active venous ulcerations, manifestations of PTS, CVD/CVI as well as prevention of post-thrombotic syndrome, orthostatic hypotension, post surgical and post sclerotherapy. These knee high compression stockings have a zipper style to make it simple for patients to put on and take off. Vairox gives you long and short options, and several sizes of medical compression hosiery.