Dyna Voltage MonitorCaracteristicas: Allows the user to track battery voltage Primary use is determining when to recharge a battery in a total loss application; commonly found in drag racing When the green light is on, the battery is fully charged; when the amber light is on, there is still sufficient voltage to operate the ignition and other accessories; when the red light is on, the battery should be charged as soon as possible Measures 1 5 8" L x 1 1 8" W x 1 2" H