Billet aluminum MAF bung for 2001-2007 LB7, LLY & LBZ Duramax. The bottom side has a 4.5" radius machined to fit any 4" or 5" tube and includes 2 stainless socket head mounting screws for the MAF sensor. Key Features: Compatible with: 01-07 Duramax MAF Bung, Air Intake, Duramax