Loose fit on magazine body. retention is non-existent - Tactical Precision Manufacturing TPM Glock .40 2 Round Mag Extension

The bottom of Glock mags are only thin plastic with the two retaining tabs, so extensions need to fit well to lock up. This extension leaves a 1mm overall gap between the two locking sides of the magazine. This allows the magazine to twist and slide left to right. I can install and uninstall the extension by hand with light pressure. The locking set screw also makes direct contact with the magazine body rather than sit directly behind it. This may be due to being designed for magwell compatibility. The P needs to be removed in TPM. Sloppy tolerances for a mag extension. I would not trust the extension to stay installed if it was dropped. The magazine compatibility is also non-existent in the product details. These 40 cal extensions are designed for Glock 22 mags by their angle.