The Zev Tech +5 Magazine Basepad allows owners of factory Glock pistol magazines to increase the capacity of their factory-built mags with five extra rounds of ammunition in 9mm magazines The Zev Tech +5 Magazine Basepad is designed based on the company’s efforts using a similar basepad for the Magpul PMAG 17 GL9 and uses a multi-piece design that provides increased capacity while retaining reliable function. Provides four extra rounds on .40 S&W magazines Fits all standard Glock 9mm and .40 S&W magazines Includes redesigned spring The Zev Tech +5 Magazine Basepad does not come with a Glock factory magazines, and users must supply their own mags.