The Assault RC Foam buster is the original foam buster design by the one and only Roger Wendling. This tool has been duplicated many times but nothing as durable and useful as this unit. The Foam Buster will help get your brand new foam inserts and or tires beat up and soft ready for use after a short period of time running your off-road or on-road tires on a drill arbor and drill motor. We suggest using the Assault RC ARC71121 for all your 12mm hex wheels and the Pilot RC Twelve 17 arbor for you 17mm Wheels. We do not suggest using wet prepped tires while beating up your foams as it could weaken the plastic. The bearings are high grade grease filled bearings that will last a lifetime under these conditions. This tool is a must have for indoor off-road racing, especially when you are seeking traction right away.