plano-convex,double-convex,plano-concave,double-concave Material:BK7,Fused Silica,ZnSe,ZnS,Si,Ge,etc.,Specification for lenses (Cylindrical Lenses) Material:BK7 ( Or Fused Silica)Design Wavelength:546.1nmFlatness: Diameter Tolerance:+0.0, -0.15mmThickness tolerance :±0.2mmClear Aperture:>80%Surface Quality:20-10 scratch and digBevel:0.25 mm x 45°Paraxial Focal Length:±2% Specifications:Material: ...