Quick view Choose Options Add the extra durability of the ARRMA 4S transmission to your ARRMA 4X2 BOOST, MEGA, or 3S vehicle using the ARRMA Metal Slipper and Metal Input Gears BOOST Box upgrade package. Then you're ready to power up and go from bashing to all-out blasting! $89.99
Quick view Choose Options Install the extra-durable ARRMA Metal Diff BOOST Box option part package and bring out the beast in your 4X2 BOOST, MEGA, or 3S basher. Included are strong, all-metal front and rear diffs with full metal ring gears, input gear, and internal gears. $99.99