Flat-convex Silicon Lens 1), Brand: HENGXIANG 2), Material: Silicon 3), N=0.5 , B=40/20 , C=0.01 Flat-convex Silicon Lens1),Material ... : Monocrystal line silicon N shape.2),Resistivity: 5-40Ω, crystallographic orientation 1113),Shape ... ),Specification: Φ6-Φ22 5),Center thickness: 1.5-2.5mm6), Precision (the highest): N=2 , N=0.5 , B=40/20 , C ...