Research & Construction X STRAP Stabilizer EXO-TECH I-FIT The ankle brace is made with i-Fit and a-Fit technology for an anatomically (right & left) correct fit. The Exo-Grid (Xternal) is a dual exterior molded support structure with Grip Tech (anti-migration), that prevents the ankle from rolling inward (Inversion) and outward (Eversion). The Exo-Grid (Xternal), along with the anchor strap, assists in preventing high ankle sprains by reducing the separation of the two lower leg bones where the ankle meets. The X- Strap Stabilizers with Grip Tech located underneath prevents the foot from shifting forward. Stephen Curry, Pro Basketball, All Star Point Guard, wears the A2-DX in practice and games. Sizing Chart: Note:- Choose a size based on your shoe size. If your measurement falls between two sizes, choose the larger one. Specify left or right.