The Quaife Torque-Biasing differential behaves as an open differential until a loss of traction occurs at one wheel. When the loss of traction is sensed, the differential automatically biases up to 80% of the engine torque to the wheel with better traction (The description "torsen" is derived from Torque-Sensing.) The operation is automatic; no adjustment is required or desired on the differential. All adjustments are made simply with springs, sway bars, and shocks. This differential has aluminum end bells and 86/94mm bolt up flanges for 86mm TRE tri-pod housings,or 94mm CV joints. Comes with a brake rotor spacer to make it possible to run the rotors out at the wheels.