Lighten crank pulley.

There are basically two types of lighten crank pulley in the market nowadays which are the one with dampener and undersized type. With the lighten crank pulley the engine load will be less so that we can feel our rev climb faster, the effect is even greater with the undersized pulley. However it's safer to install the one with dampener as it can absorb the vibration from the crankshaft like the OEM pulley so that we don't have to worry about the con rod bearing wear. So make a wise choice when choosing an aftermarket crank pulley. :)