The Break-Safe Break-Away system is designed to apply the trailer brakes and brake lights if the trailer or caravan is accidentally separated from the tow vehicle. The system has a built in battery that can be charged from the towvehicle's auxiliary line or by a battery charger. The easy to operate test button is used to indicate the level of charge in the battery. This should be hecked before the trailer is towed. Please ensure that you select the correct model for your requirements