Made of aluminum. Tapered combo spacer, 2 inch thickness, black in color, no gaskets or hardware included.

Maximum airflow and more horsepower from Wilson Manifolds.
Wilson Manifolds tapered carburetor spacers feature a computer-generated, variable-radius taper design that maximizes airflow through the carburetor and enhances air/fuel distribution for more horsepower. Part throttle performance and distribution are improved by redirecting the flow pattern created by the partially open throttle blades and gradually reducing the velocity of the air/fuel mixture entering the plenum. This allows for a smoother transition into each runner, as full throttle performance is improved by increased flow. These tapered spacers can increase flow through the carburetor or throttle body by as much as 110 cfm. Wilson Manifolds tapered carburetor spacers will increase torque, horsepower, and acceleration throughout the entire rpm range. Wilson Manifolds offers the most complete line of 4-hole tapered spacers in 390, 4150, 4500, Q-Jet, and 2-barrel adapters. This provides high performance consumers with the ability to tune their engines for the maximum performance on any application. Wilson Manifolds is the only manufacturer to offer a choice of tapered spacer heights, and produces the only fully CNC-machined billet tapered spacers on the market. Wilson Manifolds tapered carburetor spacers will benefit any vehicle that operates under part or full throttle conditions such as bracket racing using a throttle stop, drag racing, Circle Track, road racing, off-shore power boats, street/strip engines, and towing vehicles.