This is a very nice used example of the M1964 knife bayonet for use on the Spanish 7.62 mm. NATO caliber CETME Model C selective-fire rifle. The original Model A had no provision for a bayonet, but this was later added. While the blade is not very long, it definitely has a "bolo" machete profile, and the official designation in Spanish is Machete Bayoneta Modelo 1964. For more information please see Watts & White, THE BAYONET BOOK, Page 253, Item 569.
The design features an unfullered "bolo" blade, with a black checkered plastic grip and large muzzle ring to fit around the flash hider. The bayonet mounting slot is in the bottom of the bayonet, and it attaches to a unique rectangular mount on the CETME rifle. The bayonet has the correct markings on the blade ricasso, which are the Coat of Arms of Toledo and the INI> Factory Insignia.