Most utility knives are not well suited to use as offensive weapons, with the exception of some outdoor-type utility knives employing longer blades. However, even small razor-blade type utility knives may sometimes find use as slashing weapons. The 9-11 commission report stated passengers in cell phone calls reported knives or "box-cutters" were used as weapons (also Mace or a bomb) in hi-jacking airplanes in the September 11, 2001 terrorist attacks against the United States, though the exact design of the knives used is unknown. Two of the hijackers were known to have purchased Leatherman knives, which feature a 4" slip-joint blade which were not prohibited on U.S. flights at the time. Those knives were not found in the possessions the two hijackers left behind. Similar cutters, including paper cutters, have also been known to be used as a lethal weapon.