Circuit Performance CP-VS6MM-BK Bolt-in Valve Stems – When standard 0.453″ valve stems just won't do the job, grab yourself a set of Circuit Performance VS6MM Skinny 6mm Valve stems for JDM Wheels, and select German wheels. Also fits select Rotiform and Asanti wheels with 6mm valve stem holes. The stems feature an overall length of 1.6″ and an installed length of 1″ (25mm), a sleek but functional length. The VS6MM stems are leak tested, and utilize double locking nuts so they will withstand 80 PSI cold pressure, 23% more than a basic snap-in style design. Black hex style caps are included, and feature an integrated o-ring for superior seal. Ideal for Work S1R and M1R, Sprint Hart CP-R, Racing Hart, Mugen, SSR, Racing BBS Wheels, Hoshing, OZ, AC Schnitzer, and select Rotiform and Asanti wheels. Compatible with any wheel with a smaller than normal 6mm diameter valve stem hole. NOT COMPATIBLE WITH STANDARD 0.453″ VALVE STEM HOLES. Tough enough for the track, stylish enough for the show – Circuit Performance VS6MM Bolt-In Valve Stems are constructed of lightweight aluminum, with a durable finish that will hold up against the toughest track days, and is the perfect way to finish your aftermarket wheel installation. High Performance – Lightweight aluminum construction means lower rotational inertia. Aluminum valve stems are 55% lighter than equivalent valve stems constructed of copper.