This Robinson Racing Products reducer sleeve adapts a 1/8 inch motor shaft to fit a 5mm bore pinion gear, allowing 5mm pinions to be used on motors with a 1/8 inch output shaft. It is a metal sleeve designed as a drop-in bushing for 1:8 scale electric vehicles from a wide range of manufacturers. A straightforward solution for matching pinion bore size to motor shaft size without replacing either component. Features: Adapts 1/8 inch motor shaft to 5mm bore pinion Metal construction For use with 1:8 scale electric platforms 7/7/26 cs