If you're looking for an exact OEM replacement piston set for your 5.9 Cummins 2005-2007, the Mahle 224-3673WR.020 is the way to go. This piston set is constructed and designed identically to the original, so you can be confident it will fit and perform just like the factory part. Sold in sets of six, so you can get exactly what you need to get the job done right.