Originally manufactured in Germany as an HK91 semi-automatic rifle, this firearm has been given two rounds of significant upgrades. The first set of upgrades was performed by Vollmer Manufacturing (so marked on the right side of the belt mechanism housing), which converted the rifle to the HK21 pattern, integrating a belt feed mechanism, ventilated handguard with bipod rails, and reconfiguring the receiver to accept quick-detach heavy barrels. The second round of upgrades was performed by Fleming Firearms (so marked on the right side of the receiver, hidden by the trigger group) which outfitted the gun with a fully functional "shelf" pattern machine gun trigger pack installed in a "S/E/F" marked housing with cosmetic pin. Taken in total, these upgrades result in the closest possible representative of the original German-designed squad automatic weapon. Post front and "2-12" adjustable peep rear sights, a vertical foregrip installed on the forearm, and the "HK21" marking on the left side above the belt mechanism and on top of the receiver. Fitted with a textured right handed pistol grip and a fixed buttstock. Includes a few spare small parts.