The cutting edge of a vibro knife was less than a molecule wide and could inflict terrible wounds when active. It existed in several versions, including small survival knives of 18 cm blade length and bush knives of 60 cm. (HHA1.1: ABF) For safety reasons, civilian versions were required, by Manticoran law, to emit a high pitched whine when activated. (HHA2.1: TS) The Royal Manticoran Marine Corps used the M87 Vibro Bayonet. (JIR1)