SDC Signal Dynamics Headlight Module with Single H4 Harness Handles high power demand sealed beam and halogen headlights totaling up to 130 watts! Operates efficiently with only slight increase above ambient temperature at continuous max headlight power rating. Internal protection against transient voltage spikes during engine starts or charging system operation. Also drops out if voltage is too low, avoiding problems associated with low voltage. Compact Size - 2 1/4" long X 1 5/8" wide X 5/8" high, Solid State Reliability 12V DC, Weather Resistant Heat Sink Case