The trailer has five indicator lights and they require each light to be on when they are on the road. Previously, they have to sit in the cab, one by one to light up to see, now you can check through this device, membrane switch on a total of five LEDs, representing the trailer's five lights, a button to press, the corresponding LED is bright, that corresponds to a trailer lights normal.

Press the corresponding button, the corresponding LED will light up, corresponding to a trailer on the light. If all five lights are on, it means that all five lights on the trailer are working properly.

Battery specifications: 12V3.3AH lead-acid battery, green LED light when charging, red light when full, full automatic power off, circuit board to be inserted vertically in that slot .

The product has a short circuit protection function.

1.LI left lamp---corresponds to SW3

2.RI Right lamp---corresponding to SW2

3.BL Brake light---SW4

4.TL Tail light---SW1

Battery low voltage indication ---LOW BATTERY ---LB

Charging indication ----CHARGING --CH

Main Chip: HR6P61P2S2L