Knife bayonet, manufactured for the WWII era Spanish Mauser Rifles.
The hilt construction is steel, with steel "bird's head" pommel, steel crossguard with muzzle-ring as the upper quillon, lower quillon has a drum or ball finial; checkered or plain wood grips.
The blade is "bolo" shaped, single-edged, single-fullered (both sides).
Scabbard is of "blued" sheet-steel with round (oval) ball frog stud; ball finial as a drag. Matching serial number on various parts of the bayonet.