Specifications: This apparatus is used for the study of ?Resonance? in a pipe with one open side, by using water to adjust the length of the pipe. When the frequency is measured by using the tuning fork, the wave length can be measured by adjusting the water level of the acrylic resonance tube. This apparatus set consists of ?the resonance tube? with a diameter of 3.5cm, 100cm in length. 1 plastic can that is used for containing water, with a handle, which is adjustable. 1 tuning fork set.