The Wilson Combat® 1911.45 ACP Spring & Follower Kit is an easy-to-install, drop-in upgrade kit, designed to deliver superior reliability and butter-smooth feeding performance. This kit includes one high-tensile, anti-binding steel spring for jam-free operation, as well as one heat-treated, self-lubricating polymer follower for balanced shell angles, delivering exceptionally smooth feeding performance under stress. Compatible with most full-size .45 ACP 1911 magazines.