Holley 12-841 4.5-9 PSI Adjustable Bypass Billet Fuel Pressure Regulator with 3/8 NTP Ports. HP BILLET CARBURETED BY PASS FUEL PRESSURE REGULATOR. Street/Strip Carbureted Applications Two Port Adjustable from 4.5 to 9 PSI. Holley® Billet Fuel Pressure Regulators are part of a complete line of fuel system products from Holley®. They are precision machined from 6061-T6 billet aluminum for strength and durability. They feature a black bright dip anodized body and a clear bright dip anodized top for corrosion resistance and good looks. The Holley 12-841 fuel pressure regulator features 3/8 NPT in/out ports and a 3/8 NPT return port. Adjustable from 4.5-9 psi for precise fuel pressure adjustments. Constructed of billet aluminum with a black anodized base and clear anodize top for good looks. Used in systems with a return line back to tank. Use with electric pumps only. One 3/8″ NPT inlet, one 3/8″ NPT outlet and one 3/8 NPT return (or bypass). 1/8 NPT gauge port. Comparable and interchangeable with popular Holley® 12-803BP regulator. Compatible with Today’s Complex Fuels. CCS Kits are supplied with the highest quality components that meet or exceed original equipment specifications and all CCS kits are compatible with today’s complex fuel. Carburetor Collectible Specialty Thanks You for Your Support! Please before leaving Feedback. We strive for perfection and welcome the opportunity to correct any issues with your order. Your satisfaction is our #1 importance. You will receive a response within 48 hours. Please limit your questions to the products we sell.