This is a ProMag Magazine known as the AR-15 chambered in 556NATO, model RM-40-FDE.
ProMag magazines are made in the USA and backed by a lifetime guarantee against manufacturer's defects. Magazine springs are precision wound using heat-treated chrome silicon wire and each and every step of the assembly process is checked and double checked in order to maintain the same consistent level of quality.
Features:
Heat-Treated Chrome Silicon Wire Spring
Manufactured & Assembled in the U.S.A.
Easy Loading
Rugged Construction
