Mahle OE GM 6.6L Duramax R w/ PCR - STD DSL Piston With Rings Set (Set of 4)MAHLE Original pistons are OE quality and have the same great OE features such as compensated ring grooves to assure proper ring loading and oil control, as well as expansion controlled designs for small fitting clearances to reduce engine noise, wear, emissions, and improve oil control. MAHLE offers pistons ready for installation with mounted piston rings, with pin and clips included for the convenience of the engine builder. This Part Fits: Year