... =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-Φ22 5),Center ... ) More information, welcome to visit: www.shhxgd.com Flat-convex led optical lens