Size: 3.5 inch. Holes to center: 3 inch. Led Quality: 4 Leds per unit. Long life span up to 100,000 hours. Circuit board completely sealed to ensusre waterproof. Surface Mount with Screw. Meets DOT FMVSS 108/SAE requirements. Rated for 12V, tested to 13.8V. License Light on Truck, Heavy Truck, End Dump Trailer, Dump Trailer, Trailer…..