Arrma Kraton 1/8 EXB Extreme Bash Roller 4WD Monster Truck (Black)Arrma Kraton 1 8 EXB Extreme Bash Roller 4WD Monster Truck. The Kraton EXB roller is made to do one thing and do it better than any other RC car or truck and that is to bash harder than any other RC truck. Designed around a new T6 7075 aluminum chassis, new stronger a arms, and new Extreme bash differentials. The Kraton EXB roller also allows you to choose your own electronics for whatever application you end up using your Arrma Kraton EXB for.