Flat-convex silicon lens 1, Brand: HENGXIANG 2,Precision (the highest) : N=5-10 , B=40/20 , C=0.1 Flat-convex silicon lensMaterial : Monocrystal line silicon N type. resistivity : 5-40Ω, crystallographic orientation 111 Specification : Φ6.65, Center thickness=2mm, F=1.95(Center thickness=1.5mm, F=3.9/5.5)Precision (the highest) : N=5-10 , B=40/20 , C=0.1Output : 100K-200K/month