Upgrade the existing buffer and spring on your AR-15 with the Armaspec Gen 4 Stealth Recoil Spring. This drop-in replacement improves overall function and is compatible with AR-15 platforms with a carbine-length buffer tube. It features a self-contained, multi-stage design that keeps constant tension on the bolt carrier group for improved cycling resulting in a smoother, quieter operation. Unlike traditional buffer springs, the Armaspec SRS makes no contact with the inner walls of the buffer tube.