Knife bayonet for use with the 5.56 mm. NATO caliber Sturmgewehr 90, a variant of the S.I.G. 550 assault rifle. Stgw. 90 production began in 1986, eventually superseding the renowned Stgw. 57 by the mid-1990s. Like its predecessor, the Stgw. 90 quickly garnered a reputation as one of the finest rifles in its class. Stgw. 90 bayonets marmed Victorinox maker mark