Check the listing for details. Wire Pass-Through Tester Switch Component Wire Lead Conductor Open Short Alarm. Condition: New. Listed at 15.99 USD. LT002 through and through tester instructions for use 1. This machine is mainly used to dry test the wire and other conductors through and through, equivalent to a thousand multimeter through and through file, simple and convenient to use. 2. use method, the machine will be measured by the meter pen contact the two ends of the wire, if the machine issued a sound and light alarm, that the wire is conductive, the opposite is broken. On the contrary, it is a broken circuit. 3. Before the test, the meter pen of the machine will be directly shorted, there is a sound and light alarm for normal, if not, please check the meter pen or battery is If not, please check whether the meter or battery is normal. 4. This machine uses a 9V battery, you can open the back cover to replace the battery. The product principle diagram is as follows, the red and black meter pen is equivalent to the switch, when not measuring, the circuit is not on, no current consumption, a 9V battery can be used for 3-5 years. When the red and black meter pens are shorted, the circuit is on and the circuit current is about 30mA, this current will flow through the product being measured, so this product is not suitable for measuring products with microelectronic components, the 30mA current may burn out the microelectronic components. This product has no protection circuit and cannot be used to measure electrically charged products.