1. This machine is mainly used to test the on-off of conductors such as wires, which is equivalent to the on-off gear of multimeter, and it is simple and convenient to use. 2. Usage: Touch the probe of the machine to the two ends of the tested wire. If the machine gives an audible and visual alarm, it means that the wire is conductive, otherwise it is open. 3. Before testing, directly short-circuit the probe of this machine. If there is an audible and visual alarm, it is normal. If not, please check whether the probe or battery is normal. 4. This machine uses a 9V battery, which can be replaced by opening the back cover.<br><br>This product has no protection circuit, so it can't measure products. Color:As Shown Material:plastic<br><br>Package Contents: 1 * Continuity tester 1 * Special tip test lead<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.