Twisted Shifterz Pearl Kenworth Brake knobs provide a secure fit with adjustable alignment set screws. Made with a polished billet collar. Enjoy easy installation with these thread on style tractor trailer dash knobs. Simply remove the existing knobs, thread on the new ones, and tighten the jam screw to lock them in place. Get the perfect fit with these 2-1/8" diameter Twisted Shifterz knobs today! Each knob sold separately.