9+ Limited Slip Differentials provides a transfer of power to the non-slipping wheel . . ideal for most street and performance applications. Torque is applied to the non-slipping axle through clutch action to limit wheel slippage. Made of Nodular Iron, with long-lasting Raybestos clutches and a precision assembly. Because there is no clutch 'pre-load', the clutch will not chatter or cause the vehicle to pull when cornering. This design ensures a positive, smooth transfer of power for maximum traction. This product requires the use of the 9-Plus Friction Modifier (99012)