Lenses Double Concave

Unmounted Spherical Lenses With Polished Faces And Ground Edges. Suitable For Use With Optical Benches And For Other Studies In The Optics. Lens Size And Focal Length Available Are: Note: Lenses Of Other Diameters And Focal Lengths Also Available On Specific Request. (Diameter : 75Mm Focal Length : 250Mm Power : +4.00D)