This is the elbow between the turbo and the muffler for a Case 9010B, 9020B, 9010, or 9020 with 4 cylinder Cummins engine. 4bt or 4bta. I purchased this new several years back when I owned a Case 9020B, and I never got around to installation. It is brand new with the factory packaging. It had a small area of surface rust from laying around that I polished off that you will see in the pics. It is my understanding that this is a nationally back-ordered part right now. Part numbers are 158237A1 and replaces old number 150947A1.