Armaspec Gen 4 AR-15 Stealth Recoil Spring - The Stealth Recoil Spring, or SRS from Armaspec is a drop in part for AR-15 carbine length receiver extensions which replaces the traditional buffer and buffer spring. Available in a variety of weights to replace the standard buffer weights we all know, the SRS system delivers several enhancements compared to springs and buffers. The self-contained system eliminates the rubbing of a buffer spring against the inside of the buffer tube. Additionally, the unique design helps to reduce the felt recoil while firing your rifle.