Code No. 553300. 18mm/Hg Compression. Reduces the danger of thromboembolism. Designed for the recuperating patient. Sizing Chart: Medium Regular (No. 553300) - 1. Calf Circumference (Inches): 15; 2. Length (Inches): 33. An elastomer system in T.E.D. Stockings is specifically designed to speed blood flow by providing graduated compression with the most compression at the ankle and gradually diminishing pressure up the calf. These stockings are manufactured under the most rigid quality control inspections to assure the precise pressure necessary to discourage thrombus formations.