This range of externally mounted Holley electric fuel pumps are designed for use on carburettor equipped engines and are available with 3 different pressure and flow rates to suits most applications. RED Pump - The Holley RED pump has a maximum delivery pressure of 7 Psi and a maximum flow rate of 97 Gallons Per Hour meaning that a regulator is not required. The RED pump is not suitable for use with Methanol or Alcohol fuels. Ideal for mildly modified engines. BLUE Pump - The Holley BLUE Pump has a maximum delivery pressure of 14 Psi and a maximum flow rate of 110 Gallons Per Hour. Included is a Holley regulator which is adjustable from 4.5 - 9 Psi. The BLUE pump is not suitable for use with Methanol or Alcohol fuels. Ideal for heavily modified road or race engines. BLACK Pump - The Holley BLACK Pump has a maximum delivery pressure of 14 Psi and a maximum flow rate of 140 Gallons Per Hour. It is recommended that a regulator is used with this pump. The BLACK Pump is suitable for use wit