These replacement magazines for the FN 509(TM) 9mm pistol are factory originals from Fabrique National. These FN 509(TM) mags have a corrosion-resistant stainless steel body with a brightly polished interior to help the ammo stack flow smoothly, with a tough matte black exterior finish, and witness holes numbered 4 through 17 (4 through 10 on the 10-round model). Matte black polymer base pad to protect magazine if ejected onto hard surfaces High-visibility, anti-tilt follower of bright orange polymer For FN 509(TM) pistols chambered in 9mm Luger only NOTE: Will NOT work in FNS TM or FNX TM pistols Available in full 17-rd capacity or 10-rd for folks Mfg: Fn America