The Stealth Recoil Spring™ SRS™ GEN4 is a self-contained multi-stage drop-in replacement for your standard buffer and spring. The SRS™ is designed to keep the buffer spring from rubbing against the inner wall of the buffer tube providing smooth, quiet operation and the second stage helps reduce the felt recoil significantly.

Features:

• Drop-in replacement for standard buffer and spring
• Reduce felt recoil
• Keep the buffer spring from rubbing against the inner wall of the buffer tube
• Buffer mass is designed to stay under constant tension against the bolt carrier
• Made in the U.S.A.

Specifications:

• Length: 7.18"
• Equivalent Weight:
  • C: 3.3 oz.
  • H: 3.8 oz.
  • H2: 4.7 oz.
  • H3: 5.6 oz.
  • BB: 5.7 oz.
  • 9MM: 6.4 oz.
  • AR10: 5.7 oz.
• Actual Weight - Complete System (new version with stainless steel weight):
  • C: 6.2 oz.
  • H: 6.6 oz.
  • H2: 7.4 oz.
  • H3: 8.0 oz.
  • BB: 7.5 oz.
  • 9MM: 9.5 oz.
  • AR10: 7.09 oz.

Compatibility: 

• AR-15 with carbine-length buffer tube
• AR-10 in .308 and 6.5 Creedmoor with carbine-length buffer tube

Installation and Maintenance: Before installing the recoil spring, it is always a good idea to retighten the screws using either using two 3/32 hex key and fully tightening both screws at the same time or using one 3/32 hex key and using the hole in the rod for leverage.

Please Note: 

• The new GEN4 version does not have the O-ring on the weight. 
• To eliminate any potential failure points they changed the screw to a roll pin across the plastic end piece and the cap is machined on the rod replaced the snap ring with a washer.
• Most bolt carriers have a rear opening of over .60″, there are a couple of bolt carriers in the market place that have a rear opening of under .60″ and will not function with the SRS.
• 9mm Bolt Carriers ONLY: For proper function of the SRS-9 in your 9mm rifle or pistol, the extra weight on the back of the bolt carrier needs to be removed. It is held in with a spring pin.