KKmoon Portable 3.5" TFT Color LEDTest Monitor CCTV Camera Security Tester for Surveillance Audio Video Input 3.5-inch TFT LED display screen, automatically identify and adapt PAL/NTSC standard. Adjustable brightness of screen, 5V USB charging and low power warning. Audio and video input. Built-in 3.7V 2200mAh Lithium battery, the work time can reach almost 8 hours. 12V 0.5A output power, can be used as a power supply for a camera temporarily. Audio testing function, testing voice of the front end device is normal or not. If there is no video, it would turn to sleep mode after 3 minutes then you can switch in video to wake it up.