50mm Diameter Double Convex Spherical Lenses - Rapid PH30067/8, Double-convex spherical lens with a focal length of 500mm. Rapid Double Convex Spherical - Diameter 50mm - Fl 500mm
50mm Diameter Double Concave Spherical Lenses - Rapid PH30078/8, A double-concave spherical lens with a focal length of 500mm and a power of +2D. Rapid Double Concave Spherical Lens- Diameter 50mm - Fl 500mm
50mm Diameter Double Convex Spherical Lenses - Rapid PH30067/1, Double-convex spherical lens with a focal length of 50mm. Rapid Double Convex Spherical - Diameter 50mm - Fl 50mm