This is the Prism version of the old style "Chopper Box light." This classic tail light is equipped with a dual function LED cluster that acts as both a brake light and running light. The size of the Prism version housing is 4-1/4" long X 3/4" wide X 2-1/8" in height, while the size of the original style is 4-1/4" long, 2" wide, and 2" in height. The wires exit through the back of the housing. All lights come with a two stainless steel 1/4-28 bolts spaced 3.5" apart for mounting.