Extra Rounds / More Style! We’ve added some design style to the new Magazine Extensions by GS/Double Diamond. These attractive magazine extensions allow you to add up to 6 extra rounds to your existing magazines. Each comes with an extra power spring to feed the additional rounds consistently every time and is designed with a very innovative system to secure the base plate to the magazine body. The magazine base plate inserts are also designed for a universal fit allowing for custom color combinations, and increased style and functionality, available separately here. We encourage you to watch the video for a complete installation demonstration. Available for the following models: G17/22/31 – +6 9mm / +5 .40cal/.357 G19/23/32 – +5 9mm / +4 .40cal/.357 G26/27/33 – +5 9mm / +4 .40cal/.357 Big Stick 9mm – +5 9mm Please Note: The Big Stick 9mm Extension is designed to replace the factory extension on the Glock Factory Big Stick 33rd 9mm Magazine. This extension includes an extra power replacement spring and will increase your capacity to 36 rounds.