Thril PMX AR-15/ M4 30 Round 5.56x45mm Rifle Magazine Flat Dark Earth 1 Pack Polymer. The PMX technology combines impact-resistant polymer and an elastomeric strike plate to ensure maximum performance in all situations. Specifications for Thril PMX AR-15/ M4 30 Round 5.56x45mm Rifle Magazine: Manufacturer: Thril Fabric/Material: Polymer Magazine Capacity: 30 Round Caliber: 5.56x45mm NATO Gun Make: AR Platform Condition: New Package Contents: Thril PMX AR-15/ M4 30 Round 5.56x45mm Rifle Magazine Thril PMXAR30DE-30RD: PMX AR-15/ M4 30 Round 5.56x45mm Rifle Magazine Flat Dark Earth 1 Pack Polymer