The Zev Technologies Extended Magazine Base Pad is the perfect addition to your factory 9mm and 40 S&W Glock magazines. Constructed of hard anodized aluminum, these drop in replacements for the factory baseplate add 5 rounds for 9mm and 4 for 40 S&W. FeaturesAdd +5 capacity on 9mm2 piece design for ease of disassembly and reassemblyExtremely easy to install, great styling and performanceExtended magazine spring included DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.