The Advantage Arms .22 LR Conversion Kit with Range Bag and One 10-Round Mag for Gen 4 Glock® 20/21 Pistols is a complete drop-in .22LR conversion kit for your favorite Glock handgun. Designed to deliver reliable rimfire training performance without the need for another gun purchase, this kit includes a CNC-machined 7075-T6 aluminum slide for exceptional strength and reliability while maintaining a lightweight profile. The heat-treated 4140 steel barrel offers exceptional accuracy with most .22LR loads, while the steel recoil spring, guide rod, and slide stop ensure reliable and consistent operation. If that's not enough, this drop-in rimfire conversion kit includes a soft-sided range bag and one 10-round .22LR magazine. One-year warranty.