1911 spring and follower kits help single-stack USPSA and IDPA shooters refresh magazines that have started to stack unevenly. The listing includes Wilson ETM kits for 8-round .45 ACP and 10-round 9mm full-size magazines, plus Tripp .45 ACP magazine upgrade kits. Replace springs and followers across the whole rotation so every magazine behaves the same on the reload. Confirm your magazine maker and model before ordering. Fast same-day shipping on most orders at Shooters Connection.