ProMag FN Five-seveN 5.7x28mm Pistol Magazine 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. Specifications for ProMag FN Five-seveN 5.7x28mm 30 Round Pistol Magazine: Manufacturer: ProMag Gun Make: FN Herstal Gun Model: FN Five-seveN Caliber: 5.7x28mm Magazine Capacity: 30 Round Condition: New Fabric/Material: Polymer Package Contents: ProMag FN Five-seveN 5.7x28mm 30 Round Pistol Magazine What firearm models does the manufacturer say ProMag FN Five-seveN 5.7x28mm 30 Round Pistol Magazine is compatible with? The manufacturer suggests that ProMag FN Five-seveN 5.7x28mm 30 Round Pistol Magazine is compatible with FN Five-seveNProMag FNHA2-30RD: FN Five-seveN 5.7x28mm Pistol Magazine 30 Round Black 1 Pack DuPont Zytel Polymer