Listed below are the different manufactures of bayonets used with the M4 Bayonet.  The
  M8 and M8A1 are the issued scabbards.  The M10 model fits, but I doubt it was ever
  issued.  The scabbard is one area of collecting that doesn't get noticed very often.
  All the M4's are issued with scabbards, and there are diff brands and versions just
  like the M4 bayonets.

Beckwith Mfg. Co.	Manufacture  Stamping:	Eickhorn-Solingen
M10		PWH
Victory Plastics