The 20rd TorkMag is the same size as a factory 17-round magazine with +2 extension. The included baseplate allows for quick retrieval from a pouch under stress. All injection molded with metal replacement polymer made right here in the U.S. The TorkMag has ambidextrous mag catches to ensure accessibility. An AR15 mag catch is also molded into the left side of the main tube to allow out-of-the-box use with our Magdapt 17 conversion kit for pistol-caliber AR carbines. Two witness holes indicate when the mag is loaded with 10 and 20 rounds. 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.