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.
KA2284 Power & Audio Level Indicator Module
Length x Width
29mm x 21mm
AC and DC signals can be controlled by jumper