Carburetor Main Jet Extensions Screw In Style - Fits: Holley Specs: *Sold as a 4 Pack *Extensions Are Made From High Quality Brass *1/4-32 Thread Size *Made of Brass *Fits: Holley & Holley Style Carburetors Including AED, Barry Grant, Quick Fuel, Demon, Avenger and More!!! *Fits 2300, 4150, 4160 & 4500 Series Holley Carburetors *These Parts Will Come In Bulk Style Bag Packaging *Part Number: 122-5000