SIMPLE 2 WIRE INSTALLATION - Connect as close to the battery terminal as possible using the large soldered (not crimped) ring terminals. PEACE OF MIND - Built using rugged Littlefuse Varistors designed and tested for automotive applications requiring high surge current transient protection. GREEN STATUS INDICATOR = Protected, the surge protector is monitoring your electrical systemRED STATUS INDICATOR = Unprotected, the surge protector is damaged and needs to be replaced