Product Description: Input voltage: DC5V Operating voltage: approx. 30mA. Transistor Tester Control The tester is controlled by a rotary switch. Color: Black Material: Plastic The rotary switch can have 6 functions: short press, long press, left turn, right turn, press and hold left turn, press and hold right turn. A short press in the off state will turn on and test. After a test is completed, if no device is detected. Long press the switch or turn the switch left or right to enter the function menu. After entering the function menu, the left or right switch can select up or down in the item, and to enter a specific function item, short press the switch once. When it is necessary to exit from a certain function, then long press the switch. Package Contents: 1 x GM328A Transistor Tester (Note: Other products are not included. Light reflection and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3 cm.)