Spec 10.5" Stage 2+ clutch kit with aluminum flywheel and billet aluminum pressure plate. A stock clutch and flywheel assembly is 51-52 lbs, so the weight savings is great for a perfectly drivable clutch. Aside from the 20+ lbs removed from the back of the crankshaft, having a flywheel and pressure plate with wear surfaces that can be easily replaced is a bonus. No more machining or replacing flywheels and pressure plates, just replace wear surface which is much cheaper.