1. Test battery and battery voltage
2. Interior temperature
3. Two 5V 2100ma USB charging ports 4 built-in 2.1 A fuse
Color optional: bluish red, green red, all red
Suitable for model: 12-24v gm Voltage: 12/24 v Function: monitor temperature, voltage, and outlet of UBS Power connection: cigarette lighter plug type, plug and play.
​UBS output voltage: 5V 2.1 A