No gears: each sidearm is independently articulated with cushioned hyperextension stops. Engineered top and bottom straps assure personalized fit. Latex-free neoprene provides thermal compression. Open 360° padded buttress isolates and supports the patella. Bound edges prevent irritation. Perforated back panel provides heat and moisture management and all-around comfort. Exterior layer of nylon fabric for durability. Fits left or right. Content: 100% Latex-free 4.8mm Neoprene (CR) – Exclusive of binding/straps/cover fabric/hinges