Stoeger STR-9 Compact Stainless Steel 9mm Luger Handgun Magazine - 13 Rounds - STR-9 Compact Magazine, 9mm 13 Round withPinky Extension. Produced from steel with a nickel plated finish and a durable black polymer base, this mag is capable of holding 13 rounds of live 9mm ammunition for the STR-9 Compact pistols. With Pinky Extension Produced From Steel With A Nickel Plated Finish Durable Black Polymer Base