mpact-resistant polymer construction Dependable fit and finish Enhanced ergonomics Designed to deliver improved comfort and control with 24-round FNA(R) 509(TM) 9mm magazines, the FN 509 Midsize 9mm 24-Round Magazine Sleeve features impact-resistant polymer construction, engineered to integrate with your pistol's frame for seamless, snag-free performance. Plus, this magazine sleeve is easy to install for frustration-free, field-ready service! Compatible with factory 509 magazines ONLY (not included). Made in USA.