These SWORKz factory replacement outdrives are designed for the S12-3 gear differential and fit the S12-3 2WD buggy platform. The outdrives feature a slotted cup design that mates with the differential output and transfers drive to the axles. Sold as a set of two pieces. Features: Set of 2 outdrives Designed for the S12-3 gear differential Slotted cup interface for positive drive engagement Direct SWORKz factory replacement 7/7/26 cs