For optically slowing or completely stopping any object in motion, and for measuring the frequency of periodic motion. Consists of a black metal disk of 250mm diameter with 12 evenly spread radial slits extending to its edge. An axis hole for mounting a handle and a finger hole. Handle and mounting screws are included.

Discover the power of the sun with more than 10 experiments.  You can produce some serious energy with this kit.  A solar energy lab complete with converging mirror, wooden stand, clear plastic test tube and glass thermometer.  Instructions are available online.

Hollow prism is used to study, observe or compare the refraction of light in different liquids of different refractive indices.