FN America 509 9mm Luger 17 Round Pistol Magazine Black. The steel wire internal spring and anti-tilt polymer follower ensure flawless feeding while numbered witness holes allow for quick visual round counts in the field. Specifications for FN America 509 9mm Luger 17 Round Pistol Magazine: Manufacturer: FN America Gun Make: FN Herstal Gun Model: FN 509 Caliber: 9mm Luger Magazine Capacity: 17 Round Color: Black Fabric/Material: Stainless Steel/Polymer Package Contents:FN 509 9mm 17 Round Pistol Magazine FN America 20100510: 509 9mm Luger 17 Round Pistol Magazine Black