RG® High Quaity Lens and Mirror Set| Set of Concave, Convex Mirror and Concave, Convex Lenses. 50mm diameter,Focal Length-20 cm : Amazon.in: Industrial & Scientific
High Power 30MM Smooth Convex Lens 30mm Optical Glass Lens - - Amazon.com
10pcs x high Power 20MM LED Smooth Convex Lens - - Amazon.com
United Scientific Supply Double Convex Lens, Glass, UNMOUNTED, 75MM Dia / 100MM FL, Each - USS: Amazon.com: Industrial & Scientific
Anand traders Plano Convex Lens for Telescope Project 100 cm Focal Length Making Kit (50 mm) : Amazon.in: Electronics