Concave-convex Lens 1), Brand: HENGXIANG 2), Material: optical glass 3), Light transmittance: 85% Concave-convex Lens1), Material: various optical glass.2), Shape: concave, convex, flat ... , etc.3),Type: Flat-convex lens, flat-concave lens, double-convex lens, double-concave lens, etc4), Usage: optical achromatic ...