Used for the visual demonstration of the properties of wave motion and the effects of refraction, diffraction and interference. Water tank: Frame of plastic which pastes transparent glass plate, size for 38x31.5x2.6 Cm, Frequency flash source: the size is 18x7.7x7.7 cm, rotational speed by 6 to 99Hz adjustable. It has the synchronized electricity output, and causes the oscillator for synchronization. This use the power source is DC 12V-4.7A. It has the oscillator, the gearing cross rod, the remote control, the wave matches, anti-appendices, wave fitting, reflector, projection board etc