The Harmonic Balancer – GM SB Compatible – Internally Balanced – 6.750" OD is a precision-engineered crankshaft damper designed for GM small-block engines that use an internally balanced rotating assembly. This harmonic balancer helps reduce engine vibration and stabilize crankshaft rotation during operation. It is commonly used in engine rebuilds, performance builds, and replacement applications to maintain smooth engine operation and protect internal engine components.