The Springfield Armory Echelon Magazine is a standard factory replacement magazine. This magazine is for Echelon Models chambered in 9mm Luger and holds 17 rounds of ammunition. It is made from high quality steel with a polymer follower and polymer base plate. The exterior of the magazine features a new scratch and wear-resistant blacked out coating and numbered round count witness holes allow you to see how many rounds are loaded in the mag with just a quick look at the rear of the magazine. Specifications and Features: Factory Magazine Caliber: 9mm Luger Capacity: 17 Rounds Steel Body Polymer Follower Numbered Round Count Witness Holes Flush Fitting Design Wear-Resistant Black Finish