The basics of light transmission can be easily be demonstrated with two specially formulated Lucite bars - one curved and one straight. The two bars offered in this set are ideal for simply demonstrating how light is contained in optical fiber by total internal reflection (TIR). Light beams can be seen trapped and reflecting down the straight bar as well as around the bend in the curved bar. Both bars are 1 x 2 x 23 cm. Laser or laser beam box required to create light beams.