The Sport range of spares provides everything you need to fine tune a Scalextric car to get the maximum performance from it on the track These Sport pinion gears are suitable for use with most Scalextric FF motors 18 000 rpm as well as the red C8424 20 000 rpm green C8425 25 000 rpm & black C8426 30 000 rpm replacement FF motors Contains 8 9 10 11 & 12 tooth gears