Glock OEM Magazine Extension Insert Features Engineered by Glock this insert ensures secure and reliable function when using the OEM Plus Two Magazine Extension. By fitting seamlessly inside the extension it provides stability and proper alignment for the magazine spring and follower. Its precise polymer construction matches Glock's OEM standards guaranteeing consistent performance under repeated use. The insert is compatible with most double-stack Glock magazines in 9mm .40 S&W and .357 SIG offering flexibility for a wide range of pistols. Lightweight and durable it adds no unnecessary bulk while ensuring the extension functions properly. For shooters who want to increase magazine capacity with Glock's Plus Two Extension this insert is an essential factory component. Glock OEM Magazine Extension Insert Specifications Manufacturer: Glock Model: OEM Magazine Extension Insert Compatibility: Fits double-stack Glock magazines (9mm .40 S&W .357 SIG) Not Compatible: Glock 43 Function: Required insert for OEM Plus Two Magazine Extension (GLSP07151 sold separately) Material: Polymer Color: Black Packaging: Factory packaged Application: Magazine extension installation and support