This is KA2284 Power & Audio Level Indicator Module that can use to check voltage of your battery and audio level of you amplifier. you can adjust level of this meter through potentiometer. before adjust the level of battery or power supply, set potentiometer to 0 level to protect the module by high voltages.
Specifications
Input Voltage
0V ~12V
Length x Width
29mm x 21mm
Operating Voltage
3.5V ~12V
Special Features
AC and DC signals can be controlled by jumper