This is a very cool NEW pair of aftermarket red plastic lense tail light assemblies to imitate the classic 1959 Cadillac car lense. The pair comes assembled and includes the red tail lenses, Chrome steel bezels, stainless steel bulb sockets with #1157 dual filament bulbs and wiring. The diameter at the base of the bezel is 3.25" including the prongs. The overall length with lense is 6". Very easy to install on your custom lead sled or hot rod custom.