This is the new Vigor o-ring cutting tool for the Yokomo BD8 differentials. Use this tool to reduce the o-ring’s thickness to 1.5mm or 1.4mm in order to build a smooth and leak-free unit. Using the 1.5mm setting will create a smoother diff feel than stock while the 1.4mm setting ensures an even smoother diff action. This tool was developed for the original Yokomo BD-500G0 o-rings. Please ensure you use a fresh cutting blade to cut your o-rings!