The Wilson Combat® 1911.45 ACP 8-Round Spring & Follower Kit is a simple-to-install, drop-in upgrade kit that is created to provide greater dependability and smooth feeding performance at a competitive price. It is compatible with most.45 ACP 1911 magazines. This kit’s high-tensile steel spring and heat-treated polymer follower are designed to provide remarkable reliability straight out of the box and provide long-lasting durability, lightning-fast feeding performance, and smooth, jam-free operation.