Abstract: A self defense weapon comprising a base and a striking arm connected end to end by a pivot. The pivot allows the striking arm to move in only a single plane, between a collapsed position in which the striking arm is partially contained in a concave portion of the base, and an extended position in which the striking arm is fully extended. The striking arm is prevented from rotating past the extended position by the abutting of the two ends. Thus the striking arm is prevented from injuring the user's hand by having a length short enough that it does not overlap any of the handle in the closed position. A safety chain connects the base to the striking arm near the pivot, and prevents the striking arm from flying away from the base if the pivot breaks. A hook at the end of the handle fits around the user's hand, preventing an attacker from taking the weapon away from the user. Lastly, a key ring attached to the handle helps to disguise the function of the invention.