(click to enlarge) Type: Arm Reamer Series: profiTOOLS R/C Tools Tip size: 4.0mm Tip length: 120mm 4mm Arm Reamer for 1/8 scale RC car arms A binding suspension will negatively influence the handling of any R/C car. The new Arm Reamer is the latest addition to the professional Hudy tool line. Designed specifically for R/C use, this reamer will precisely resize plastic holes without creating excessive slop, allowing you to build a perfect free-moving suspension. (click to enlarge) Tool detail The tool is specially designed and hand groung to create sharp micro scurfies on the surface of the tool pin to precisely size plastic without tearing, stressing or over-sizing the hole of the suspension arm. (click to enlarge) How to use 1. Insert the head of the tip into the suspension arm hole, then smoothly and gently push inward while rotating. (click to enlarge) 2. Continue pushing the tool though the hole until you reach the tool handle. (click to enlarge) 3. Slowly reverse direction and pull out the tool while rotating. You will now have a perfect, non-binding suspension arm.