This harmonic balancer is designed for BluePrint Engines small block chevy compatible engines that are internally balanced, meaning the crankshaft itself provides all necessary counterweighting. No external balance weights are included or needed on the balancer. This size is typical for high-performance street or light race applications. The 6.750" diameter offers a balance between weight and damping performance, helping reduce torsional vibration without excess rotating mass. Comes with mounting hardware and timing pointer. This 6.750 size offers some space saving convenience, as well as less rotating mass, vs our standard BPP350 damper. It's functionally identical to the BPP350, with the aforementioned benefits, and even comes with a timing pointer!