Dogma
Forum Sage
The Truck Lite product was originally designed for use in the military HUMVEE, so it was a 24-volt design. They have since done 12-volt lights and gotten them DOT certified.
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IIRC, it has always been designed to accept either 12 or 24V. I don't remember how much voltage it takes to damage it.
As far as mechanical durability, they were definitely designed for off-road usage on military vehicles. I had a gen 7 Truck-Light lamp mounted when I low-sided this fall, and it has shown no signs of failure in the several dozen hours of use since. I know some signal lamp replacement LED components haven't stood up to vibration well, but the Truck-Light headlamps are nearly bullet-proof. Nearly, as in, they keep functioning after being shot through.