Version 2 gearbox shell with bearings. The ULTIMATE® Upgrade Series gearbox shell is cast in high-strength casting materials to ensure the box is able to endure the extra stress an upgrade will put on the box. The gearbox are equipped with taps controlling the lining of the case preventing the box from twisting under the stress. Unique serial numbers High strength hex-screws High performance 8mm steel bearings ULTIMATE® selector plate Low friction chromium plating For in-depth information on ULTIMATE® Upgrade Series, see catalogue.