Electrical Tester Pen Digital AC/DC Voltage Detector Non Contact Power Cable Testing Electric Compact Pen Meter 12-1000V Current Electric Sensor Test Pencil. Specification: Material: ABS. Color: Red, Yellow. Batteries Included: No. Breakpoint detection. AC voltage sensing. Sensitivity adjustment. Zero line recognition. Features: Non contact AC voltage sensing: When a nearby AC voltage is sensed, a Repid beep will sound and the sensor head will flash red. Accurate test and stable performance, triple alarm with sound and light screen. Multi-function zero line recognition: Fireline: it will beep quickly when inserted, and the pen tip will flash red neutral line there is no buzzer when inserted, and the pen tip will not flicker. Usage: 1. Press the position of the black square block. 2. While holding down, push the pen coverup to install 2AAA batteries. Package included: 1 x Electrical Tester