Using straight-cut cam gears will reduce the side load on your camshaft bearings, and produce more horsepower.  The steel gears are stronger than stock aluminum or magnesium gears, thus can hold up better to stronger dual valve spring applications better, and high lift cams.  This set is non-adjustable, so the gear is bolted directly on to the cam with hardened bolts, which are provided.  Matching crankshaft gear provided, as well.

Using straight cut steel gears does produce more noise from the engine, so be aware of this.  Some people really like the distinctive turbo style "whine" they produce, while others prefer a quieter engine.