The Armaspec Stealth Recoil Spring SRS is a self-contained multi-stage drop-in replacement for your standard buffer and spring.  The Steal Recoil Spring is designed to reduce felt recoil as well as keep the buffer spring from rubbing against the inner wall of the buffer tube.  

Due to rifle, pistol and bolt carrier manufacturer variances, this product may not work in all rifles.

SRS - H2 4.7 oz Equivalent