Solid state construction, no bulbs to break or burn out. 100,000 hour rated life. Fully sealed, submersible construction. Potted circuitry(coated and sealed) protects against moisture, corrosion, and vibration. Lower amp draw than incandescent lights. Designed to directly replace 440-series incandescent lights. Integral, dedicated side marker diode. Exceeds all DOT rear lighting and reflex requirements for trailers less than 80 in wide. 4-1/2 in width x 4-1/2 in height x 2 in depth.