* Digital display gives exact reading with no guessing or errors; Wide measuring range and high resolution. * Automatic stop flashing to save electricity and improve flash tube lifetime. * Internal / external triggering fast conversion; x2 and ÷2 button for fast adjustment. * Use photoelectric signal while external triggering, achieve automatic tracking function of the pattern. * Use microcomputer technology, emerging technologies, anti-jamming technique and other advanced technology, it can measure the rotative velocity without contacting the object.