ProMag Rifle Magazine Colt M4 22 .22 LR 30 Round Black 1 Pack DuPont Zytel Polymer 30RD. It is constructed of DuPont Zytel polymer with injection molded mag follower and mag spring formed from chrome silicone wire. NOTE: This mag will not work with Ciener and G.I style 22 conversion rifles. Specifications for ProMag Colt M4 22 .22 LR 30 Round Rifle Magazine: Manufacturer: ProMag Color: Black Fabric/Material: Polymer Magazine Capacity: 30 Round Caliber: .22 Long Rifle Gun Model: Colt M4 Condition: New Package Contents: ProMag Colt M4 22 .22 LR 30 Round Rifle Magazine What firearm models does the manufacturer say ProMag Colt M4 22 .22 LR 30 Round Rifle Magazine is compatible with? The manufacturer says that ProMag Colt M4 22 .22 LR 30 Round Rifle Magazine is compatible with Colt M4ProMag COLA30-30RD: Rifle Magazine Colt M4 22 .22 LR 30 Round Black 1 Pack DuPont Zytel Polymer