adidas Lady Adizero Feather Tennis Shoes Synthetic Upper - To help your feet breathe while you on the court. EVA tongue - For maximum ventilation and comfort to keep your feet cool and comfortable adiTUFF - This is an abrasion resistant material in the toe-upper. This is where indoor court shoes seem to wear out quickest due to dragging of the feet. This increases durability. adiPRENE + - Located under the forefoot for greater propulsion and efficiency as well as better toe-off. TORSION System - Gives midfoot integrity and with full forefoot adiprene plus maintains effective propulsion.