PCB Board Size: 7.3 x 6.8cm (W / L) Shell Size: 11 X 6.9 X 41.5cm (L / W / H) One way adjustable signal generator output. Convenient to provide the pulse signal. With a logical pen function. For convenient the logic level of test circuit. With one way buzzer. You can test the wires on and off (connect the wires to the power positive and signal input, the wire on - the buzzer sound). You can also test the low-frequency signal (input the signal from the signal input, if there is a signal, the buzzer sound).