Designed to deliver flawless feeding performance, the Wilson Combat® 1911 ETM 9mm 10-Round Spring & Follower Kit is an easy-to-install, drop-in kit, compatible with Wilson Combat #500-9 and #500-9CD magazines. Featuring a high-tensile steel spring and heat-treated polymer follower, this drop-in kit offers quick, tool-free installation while simultaneously providing smooth, reliable, field-ready service you can depend on. Compatible with all Wilson Combat 1911 ETM magazines.