... Brand: HENGXIANG 2), Material: Silicon 3), N=0.5 , B=40/20 , C=0.01 Flat-convex led optical lens 1),Material ... : Monocrystal line silicon N shape2),Resistivity: 5-40Ω, crystallographic ... orientation 1113),Shape: concave, convex, flat, etc.4),Specification: Φ6-Φ ...