Magpul Supplemental Impact/Dust Covers for the 5.56x45 PMAG 30 AR/M4 GEN M2 MOE, PMAG 20, and EMAG are designed to minimize debris intrusion and protect against potential cartridge damage during storage and transit. NOTE: These will also fit all older pre-GEN M2 variants of AR15/M16 PMAG (with Black or Foliage Followers). This cover will likewise fit the PMAG GEN M3 but, because it's a slightly different design, it will not adequately seal that magazine against debris intrusion.