Although replaced by improved variants like the Ruger American Pistol and the Ruger Security-9, the Ruger SR Series of guns still provide reliable range and personal-defense service to owners, and these all-steel magazines give owners of these guns a chance to expand their range practice with standard- and extended-capacity options. The Ruger SR9 steel magazine is designed for use with 9mm cartridges only and have a magazine body made from heat-treated carbon steel. The magazine is treated with a black-oxide finish that combats corrosion and premature wear. Inside each Ruger SR9 steel magazine, you'll find a spring formed from heat-treated chrome-silicon wire, as well as an injection-molded follower. The magazines are available with a 17-round and a 32-round capacity and are made in the USA.