USGI M4 / M16 / AR15 30-round EPM brown aluminum magazine
The Enhanced Performance Magazine (EPM) from Center Industries, CAGE code marked G9199
Army engineers and scientists optimized the EPM to work with the M4/M4A1, M16 rifle, and standard military 5.56mm small arms round, the M855A1.
The M855A1, known also as the Enhanced Performance Round (EPR), has been in use since 2010.
Following the EPR's release, engineering tests of M4/M16 rifles firing the M855A1 showed that the weapons were sensitive to the EPR's steel tip. A Picatinny Arsenal, N.J. engineering team subsequently made a design change to the magazine that corrected this issue. The EPM eliminates weapon wear caused by the steel-tipped M855A1 at the upper receiver/barrel extension interface, a condition discovered during laboratory testing.
The EPM is a brow to tan-color and has a blue-gray follower. The latter is the spring-loaded plastic component that positions each round up into the lower receiver of the weapon. Each magazine holds a maximum of 30 rounds.
(portions of the above description, courtesy of US Army)
New, in milspec plastic, but expect handling marks on the magazine, which is normal for DOD contracts. This is military surplus. The real deal.