Manufactured in the USA using the finest equipment and tooling, ProMag Replacement Magazine for GLOCK Pistols bodies are constructed of high-impact polymer with a steel insert for lasting durability and performance. State-of-the-art polymer followers ensure dependable feeding, while chrome silicon springs deliver years of reliable service. Each magazine is backed by a lifetime warranty, so you can count on them to perform in your GLOCK pistol. Made in USA. High-impact polymer construction Steel insert for enhanced rigidity Polymer follower Chrome silicon springs Lifetime warranty