• Interchangeable restrictor rings (patent pending) in 35mm, 37mm, and 39mm I.D. enable custom-tuning of Venturi pressure differential to optimize any engine build, level of boost, or operating altitude.

• For use with our ‘convertible’ SU HIF44 ram pipe and air cleaner or snorkel adapter

• CNC machined from 6061-T6 aluminum billet

Made to exacting tolerances in U.S.A at family-owned shop.

**NOTE TO INTERNATIONAL CUSTOMERS (INCLUDING UK): up to 2 (two) adapter kits will fit in a single, flat-rate U.S.P.S. box. If ordering multiple products, please email us about consolidating items into a larger box to save on shipping charges.

*NOTE TO UK CUSTOMERS: The European Union may impose vat and handling fee.