The Holley electric fuel pumps provide constant fuel flow with no pulsation. Each have externally accessible pressure relief valves and are more tolerant of contaminated fuels. Each pump weighs approximately three pounds and includes a mounting bracket. The "red" pump flows 97 gph (free flow) and 67 gph at five psi. The "blue" pump flows 110 gph (free flow) and 70 gph at nine psi and includes fuel pump pressure regulator part# CH20503. These pumps are not designed or recommended for use on fuel injection systems. Use of safety shut-off switch, part# CH20505, is strongly recommended.