3 1/2" Turbo Intake Horn for the 2017-2019 L5P Duramax with factory style Turbo. The OEM plastic intake horn is 2.4" diameter and we experienced a 25HP Gain with our 3.5" Horn when used with a Max Effort Tune. Tuning not required, this horn will work with plug and play tuners or OEM calibration. Additional Attributes: GTIN: Material: Steel Mounting Hardware Included: Yes Finish: Powder Coated Prop 65 Y/N: Y Extended Information: Emissions : EPA Eligible Life Cycle Status: Available Only While Supplies Last Packaging: Quantity of Each: 1 Package UOM: EA Dimension: 14 x 8 x 6 inches Weight: 5 PG