The Edelbrock Open Phenolic Carburetor Spacers are used where more plenum volume or more carburetor-to-plenum floor distance is required. It allows you to space your carburetor above the intake flange to increase plenum area for more torque and horsepower. This high-tech, open, black, phenolic carburetor spacer is 2 inch thickness and can withstand extreme temperatures. It enhances low RPM torque and throttles response and dampens reversion effects on the carburetor. The phenolic plastic construction provides superior heat insulating properties and reduces heat transfer to the carburetor.