Consisting of a straight, extending club, mostly used by guards and police, they serve many purposes, such as riot control and criminal arrests. They still have their use today.
Although not very powerful, it has an extremely fast swing speed. Probably best used against opponents who aren't armed with melee weapons themselves as they will often block, stunning you for a few precious seconds. For this reason it's best to use V.A.T.S. attacks on other melee opponents.
The following is based on Fallout 3 cut content and has not been confirmed by canon sources.
O'Grady's Peacemaker - It was supposed to be used by a Vault 101 security guard called O'Grady, who is in the game, but was cut from the final version of the game.
End of information based on Fallout 3 cut content.