Replacement O-Ring for Duramax VGT Turbo inlet. Used on the following WCFab Kits: S400/Stock twin kits 2004.5-2016 models, Stage 2 intake kits for 2004.5-2010 models, VGT Turbo Inlet Horns for 2004.5-2016 models, One Piece Intake for 2011-2016 Models