Similar in construction to the "Big Frigger" power fist, this pneumatic-type power fist is a large metal glove with a piston and ram built in above the wearer's fist. The piston shoots the ram forward with every punch, allowing the fist to deal more damage than most unarmed weapons. Unlike the Big Frigger brand, this pneumatic-based power fist doesn't use energy cells to operate.
Two are on a small dock to the east of the Citadel, in the personal footlockers, which are locked with Very Hard locks. The key to the footlockers can be found next to an ammunition box in the nearby sunken boat.
If the player character targets an enemy in V.A.T.S. that is below their knees, the player character will not punch, but kick the enemy. (Although the sound of the power fist hitting the target is still present.)
On the side of the power fist are carved in kill counts, 33 in total.
If viewed in 3rd-person while equipped, there are two small exhaust jets coming from the back of the power fist, indicating an internal engine of some sort.