Notes:1.Built-in sensor, when nearby AC voltage is detected,The green light will flash and an alarm will sound.2.Neutral wire line Set the gear to O, when the test pen is inserted into the hole, the red light is not on, it is the Neutral wire line 3.live wire Set the gear to O, when the test pen is inserted into the hole, the red light flashes to be the live wire 4.Battery detection Turn to the H position, put your finger on the Contact pole, place the electric pen on the positive pole, and place the other hand on the negative pole. The light is on to indicate that the battery is fully , and the light is off to indicate that the battery is dead. 5.Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you!6.Please allow slight measuring deviation due to manual measurement. Specifications: Material: Plastics Size: 141x18.6x16mm color:black +yellow Package Contents: 1 x Test Pencil Only the above package content, other products are not included. Note: Light 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.