Fleece Performance 2017+ GM Silverado 2500/3500 6.6L L5P Duramax High Flow Intake HornGain up to 10 additional RWHP with our cast aluminum high flow intake horn for the 2017 2019 L5P 6. 6L Duramax! Our intake horn directly replaces the smaller (2. 4" diameter) plastic molded stock intake runner with our larger (3. 3" diameter) cast aluminum model. Kit Contents: Cast aluminum intake horn Square cut O ring Billet aluminum fitting for PCV connection M8x1. 25 mounting hardware Application Notes: This intake horn is a direct replacement for