This ETS 9mm magazine is constructed from an advanced polymer material. This advanced polymer is extremely impact resistant and won't crack or break when dropped. This polymer was also made to be very resistant to harsh chemical and UV rays, as well as withstand extreme cold and heat. This magazine's translucent body allows you to see your ammo count and type at any time. Another feature of this magazine is that it is creep resistant, meaning that the feed lips and body won't spread when being stored long term even when fully loaded Features: Fits the Smith & Wesson 9mm M&P Extended 30-round capacity Base plates interchangeable with ETS line of 9mm double stack magazines Due to the wide variety of extensions for Glock, our mag base is designed to be compatible with Glock extensions Easy disassembly with our specially designed base plate Ergonomically designed floor plate makes it easy to grab from mag pouches Lifetime Warranty