UNIVERSAL MOUNT EITHER ON TOP YOUR ROOF OR MAYBE INSIDE ON THE CEILING OF THE CAB , THE INSTALLTION INSTRUCTIONS ARE SEALED INSIDE PLEASE CLICK ON SELLER DETAILS FOR ALL MY AUTO STUFF The third brake light assembly is a tail light assembly designed by GM specifically for use on cars and trucks. This essential component ensures that the vehicle's braking system is functioning properly and provides visibility to other drivers on the road, enhancing safety and communication while driving. The brand's reputation for quality ensures that this assembly is reliable and built to last, making it a crucial part of the vehicle's lighting and lamp system.