Flush fit for Smith & Wesson 9mm M&P (does not fit the single stack S&W M&P Shield).Standard 17-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