Billet Aluminium Interior Items: Give your ride that "resto-custom" look with these great looking 6061-T6 billet aluminium handles, knobs, buffer rings, etc. Made to look like an original vintage item but milled from solid billet aluminium. The door/window winder buffer rings and the door pull knobs are polished while the rest of the knobs are a machined finish that gives you just the right contrast and looks.