Function 2-channel FM stereo transmission Power-off memory function working frequency display Input volume and transmission frequency are adjustable support wide voltage supply working current, small emission efficiency, high power supply, Restore factory settings ultra low back noise Instructions for use: - Key: short press, frequency reduction, 0.1MHz; + key: Short press, increase the frequency by 0.1MHz, long press, restore factory settings; VOL button: long press, enter the input volume adjustment state, a total of 5 files, through the +- button to adjust; Press any key to wake up the backlight. After the backlight is on for , it will automatically turn off the LCD screen. If there is no operation for 3 minutes, the display will be turned off automatically. Product Two-channel stereo FM transmitter module Working voltage: DC 3V-16V Working current: 17mA Colour:Black Material:PCB Size:49mm x 31mm Package Contents: 1* FM transmitter board 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.