Plano-convex, a collimated light beam passing through the lens transfer to a spot behind the lens. we also called a positive or converging lens. The distance from the lens to the focal points(mentioned as spot) is the lens focal length, which is commonly abbreviated f in diagrams and equations, and normally we can mentioned in the specification as EFL. PHYO OPTICS supply Plano-Convex lens in N-BK7,Fused Silica,CaF2,SF11,H-BaK4,H-BaK7,etc