This is a stand designed to hold 50mm diameter lenses for experiments with optics that I designed for my friend Hans who is a teacher. The stand can be clipped onto the edge of a meter stick so that measurements between lenses can easily be made while they stay aligned. The stands can double as feet to support the meter stick, or even holders of a light source such as a flashlight or laser.

My unique design even accommodates all thicknesses in a standard pack of lenses such as this one sold on Amazon.com: http://www.amazon.com/gp/product/B00657LW8G?ie=UTF8&camp=213733&creative=393177&creativeASIN=B00657LW8G&linkCode=shr&tag=theplamik-20&qid=1360550742&sr=8-1&keywords=lens+set. This was no small feat! Whether thick or thin, convex or concave, this lens holder will hold them well.