These wrist pins are 22 grams lighter than the stock wrist pins. One end of the pin is capped. Which when installed with the capped end up will eliminate the volume of the wrist pin from the crankcase. This increases the compression in the crankcase enhancing horsepower. The fact that the pin is lighter also adds to horsepower as well as less ware and tear on the motor. These pins will fit 2.5 Mercury pistons forged and cast, they will not fit Mahle 2.5 pistons.
