The USB charger can be use to recharge two electronic devices at the same time. Of course it will also keep a Full HD video recording with audio of everything that goes on into your car.
The built-in battery offers 20 minutes of recording, it is made to save the video if the car is turned off for a few minuntes and to avoid interruption and missing recording when the car is shutted down.
This unit include a 16Gb memory card within its accessories and could accept up to 64Gb.
16Go = 3 hours of driving time
64Go = 12 hours of driving time