In addition to increased ground clearance, portal boxes make gear changes easy. With this set you can swap out the internal portal gears in the front portal boxes and improve your UTB18 Capras steering radius and climbing ability. With the front overdriven, the front tires will spin slightly faster than the rear and help pull the front faster in turns, resulting in a tighter turning radius. The supplied 25T/16T metal gears are 48 pitch. Two gears included in each set.