ProMag Industries ProMag, Magazine, 5.7x28MM, 30 Rounds, Fits FN FiveSeven 20 Rounds Magazine With 10 Rounds Extension, Black FNH-A2 ProMag magazines are made in the USA and backed by a lifetime guarantee against manufacturer's defects. Magazine springs are precision wound using heat-treated chrome silicon wire and each and every step of the assembly process is checked and double checked in order to maintain the same consistent level of quality.