The PMAG 21 GL9 is a 21-round Glock 9mm handgun magazine featuring our proprietary all-polymer construction for flawless reliability and durability over thousands of rounds. Meeting the overall length requirements for a 140MM competition magazine, the PMAG 21 GL9 offers additional capacity without the need for expensive extensions. Includes a high visibility, controlled-tilt follower, a stainless steel spring, and an easily removable floorplate for cleaning. Also includes a paint pen dot matrix for magazine marking, ridged floorplate edges for better grip, and capacity indicator windows. Drops free when loaded or unloaded. The PMAG 21 GL9 is compatible with all full-size, compact, and sub-compact double-stack Glock 9mm variants with some protrusion below the grip.