Hermetic lens-to-housing seal, Fits all competitive and popular mounting devices Twist-on mounting for easy installation, 12 volt version features a 12,000+ hour bulb Optic version only, meets PC function only when mounted at a 45° angle, recommended bracket: 43690; Cross to: KD 5710101, Peterson 143A, Signal Stat 1011A, Truck-Lite 10205Y, Truck-Lite 10208Y