CNC machined in-house from billet aluminum, these MAF housings are perfect for use in upgraded turbo cars with larger injectors and appropriate software. Features: Precision CNC machined to the tightest tolerances. Constant 85mm inside diameter for use with most K04/BT software. 3.5" or 89mm OD hose connections. Precisely machined flange for Bosch MAF element. Engraved "034Motorsport" logo. Fitment: 2000 - 2000.5 Audi S4/RS4 (B5) 2.7T 1998 - 2000.5 Audi A6 (C5) 2.7T Please Note: Optional airbox adapter pieces designed to work with either the factory S4 or RS4 airbox are sold separately. RS4 Airbox Adapter S4 Airbox Adapter We also carry an 85mm MAF housing for the later Hitachi MAF element, which is available here: MAF Housing, 2.7T Hitachi, 85mm ID Does not include MAF Sensor! EMISSIONS NOTICE This product is sold for racing use as well as use on vehicles not registered for on highway use. By purchasing this product, you understand that this product is sold for racing use as well as used on vehicles not registered for on highway use, and that it is not legal for use on highway or street vehicles.