This used Toyota/TRD OEM Helical Limited-Slip Differential 'LSD' for the C-Series (C56, 59, 60, 64, 66) and S54 transmissions will allow you to put power to the ground much more efficiently, especially when exiting corners. Reduces wheel hop and understeer as well as unpredictable handling in the corners. An LSD is an excellent addition to any car even near stock power levels but is absolutely critical after the addition of forced induction. This is a helical LSD so it only acts when power is applied- your car will drive smooth as butter in parking lots and during normal driving. Also, being a helical-type differential, no maintenance is required. This unit is identical to the factory LSD available in the Lotus Elise/Exige.