Trans-Dapt 1" Holley AFB Ported Torque-Curve Spacer is made up of CNC machined aluminum and is used to adjust the air to fuel ratio of the vehicle to best suit the environment, driving condition. This hamburger torque-curve spacer is designed to increase the performance and improves the fuel efficiency of the vehicle. It is provided with a lifetime warranty and improves the overall performance regardless of the number of power parts installed.