Street/Strip EFI Applications Two Port Adjustable from 15 to 65 PSI Boost Reference - 1:1;Adjustable from 15-65 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; Includes fitting for manifold reference; Use with electric pumps only; (1) -8 an o-ring inlet, (1) -8 an o-ring outlet, (1) -6 an o-ring return; 1/8" NPT gauge port; Designed for use with the Holley HP in-line fuel pumps or other high pressure electric pumps where return line is needed; Mounting bracket included;