These Zastava Arms AK-47 7.62×39 Polymer 40 round Magazines are newly manufactured in Serbia and imported by Zastava Arms USA. These are military grade 7.62×39 40rd black polymer magazines. The polymer frame contains steel reinforced rear locking lugs as well as a steel BHO (bolt hold open) follower. These magazines are used by Serbian military special forces and have passed rigorous tests. They are tested at high and low temperature ranges and must exhibit consistent strength, resistance to shatter, and lubricity from -40˚ C/F to +60˚ C/140˚ F.