Two crystal mikes one is used to start theming and another one is used to stop the ming when a sound frequency is generated by a hammer and a metallic plate. A 3*1/2 digit display with microsecond and millisecond provision to measure the time. The operating voltage for the instrument is 9V DC. The whole assembly is fixed inside a high-grade metallic sheet with ABS side cover. Two crystal mikes with a set of hammer and plate are supplied with the instrument.