This is a ProMag Magazine chambered in 556NATO, model RM-40-SL.
You want it" ProMags probably got it. ProMag auxiliary magazines help keep you armed and ready. Whatever the firearm - be it for recreational "plinking"" competition shooting" or law enforcement - ProMag is the one source you can count on.
Features:
Precise Manufacturing
Long Term Reliability
Durable Construction
High Capacity
