Introduction: ARRMA makes it easy and affordable for drivers of ARRMA 4X2 BOOST, MEGA, or 3S vehicles to continue on the path to higher and higher levels of performance — for example, by upgrading the transmissions with even greater durability using the ARRMA Metal Slipper and Metal Input Gears BOOST Box upgrade package. Its strong metal gears give your transmission the additional toughness needed for stepping up to higher-speed, higher-performance brushless power. These are the same metal slipper clutch and metal diff input pinions as those used in 4S ARRMA vehicles. The ARRMA BOOST Metal Slipper and Metal Input Gears BOOST Box prepares your 4X2 BOOST, MEGA, or 3S transmission with the strength to handle more powerful motors, allowing you keep growing as a driver while using the same ARRMA vehicle you already own — upgraded for amplified ARRMA bashing performance. Features: Stronger transmission gears for using more powerful motors Durability proven in 4S ARRMA vehicles Easy to install — video instructions available online Bonus ARRMA BOOST decal set included in package Experience amplified ARRMA RC bashing performance :   The Metal Slipper and Metal Input Gears BOOST Box is recommended for any of the following ARRMA 4X2 MEGA BOOST basher vehicles after upgrading to 3S brushless power using the complete 3S Brushless BOOST Box or Metal Slipper Power Module BOOST Box with a suitable brushless system