Introduction: Their all-terrain toughness enables ARRMA vehicles to easily outlast other RC bashers. Exciting speeds are always possible right out of the box, but when you're ready to take your ARRMA 4X2 BOOST, MEGA, or 3S basher to even higher speeds with more powerful motors, ARRMA is ready with the extra-durable ARRMA Metal Diff BOOST Box option part package. The ARRMA Metal Diff BOOST Box upgrades your model to 4S metal gear specs, giving it the powertrain durability for bringing out the beast in your ARRMA RC basher. The ARRMA Metal Diff BOOST Box comes ready to install following the step-by-step guidance in the online assembly video. Yokes are included, along with a bonus sheet of ARRMA BOOST decals. Use the ARRMA Metal Diff BOOST Box and other ARRMA BOOST Box option packages to raise your ARRMA model's performance to higher and higher levels — where you go beyond bashing into blasting! Features: Metal gear toughness for using more powerful motors Ready to install with yokes included Easy step-by-step installation video available online Sheet of colorful ARRMA decals also included Keep growing your skills with amplified ARRMA performance :   The Metal Diff 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 plus a suitable brushless system