Replacement O-Ring for Duramax VGT Turbo inlet.Used on the following WCFab Kits: Legacy S400/Stock twin kits 2004.5-2016 models, Stage 2 intake kits for 2004.5-2016 models, VGT Turbo Inlet Horns for 2004.5-2016 models, Stage 2 & 3 High Flow Bundle Kits for 2006-2010 models, Legacy One Piece Intakes for 2011-2016 models. These seals are also used on intake runner flanges of WCF100693 2001-2004 LB7 Billet Y-Bridge Kits (qty. 2 needed for installation).