Ammco #3904 Stamped Brake Lathe Centering Cone 1.703"-2.750" + Free Shipping Preowned/used. Good condition. Has "3904" stamped in metal on large ring. 3904 Centering Cone 1.703" x 2.750" (43.26 x 69.85mm) 1" Bore No stock photos. You will receive the actual centering cone pictured. Please see all photos. Free shipping via USPS.