Robust & light made of high impact plastic. Adjustable legs. Use over an OHP. Kit includes: ripple generator, motor & gear drive. Adjustable phase relationship between ripplers. Speed control - use rheostat Motor 3V dc. Set of barriers includes, flat, angle, parabolic & circular. Set of ripplers to create various types of ripples. 6 single point, 1 straight & 1 comb (saw tooth) Window area: 380x265mm