Using only three parts--a laser-welded sealed housing, an internal inertia ring, and highly viscous silicone fluid between the two--these SFI-approved Speedmaster Balancer can control all crankshaft vibration, not just a limited frequency range. As a result, you get reduced wear on the main bearings and timing gear, more stable valvetrain operation, and less chance of crank failure.This damper is internal balanced; the term internal balanced damper"refers to the lack of any built in weight or offset in the casting. When identifying your existing damper, (balancer) you must look on the backside."This is not"visible"if the damper is"mounted on the engine."If your damper has no offset in the casting or weight, then you have an internal, (neutral)"style damper. If you do see the offset in the casting or a weight, you have what is classified as an external damper. They are perfectly balanced, hence the term neutral.