KNS Precision Adjustable Gas Piston System- M92 Black. The patent-pending KNS Precision Adjustable Gas Piston System is a replacement for the AKs piston head that attaches to the bolt carrier in about 10 minutes with no major gunsmithing or permanent modification required. KNS Precision designed these Rifle Parts to grant the user an extremely wide range of gas adjustment for suppressed and unsuppressed use as well as a variety of different kinds of ammunition. A good rule of thumb to determine if our piston will be useful is if your gun throws the brass more than 15 feet. This can but not always signify excess gas pushing the carrier back at a higher velocity and pressure than is needed for effective operation. Most (but not all) AK's are over-gassed. This causes more recoil more wear and tear and less controllability. Many users are surprised to feel the difference in how their over-gassed gun shoots with our Adjustable Gas Piston System installed. There are many variants within this family of weapons and the only way to truly make certain you are getting the right system is by precisely measuring your existing piston and comparing them to the chart. There is no need to remove or replace your gas block for adjustability. Just change the piston and go shoot. Specifications for KNS Precision Adjustable Gas Piston System: Manufacturer: KNS Precision Finish: Black Fabric/Material: Stainless Steel Gun Model: AK-74 AK-47 Country of Origin: USA Features of KNS Precision Adjustable Gas Piston System: Key Benefits: Tool-Free Adjustment Reduces Recoil Tune almost any AK for suppressed use Decrease cyclic rate for full-auto fire made in specialized factories 922r Compliance Part Piston head assembly made from corrosion-resistant stainless steel All surface parts nitrided for durable low-friction & easily-cleaned operation Patent Number 10330480 Package Contents: KNS Precision Adjustable Gas Piston System What firearm models does the manufacturer say KNS Precision Adjustable Gas Piston System is compatible with? The manufacturer says that KNS Precision Adjustable Gas Piston System is compatible with AK-47 AK-74KNS Precision AGP-A-4: Adjustable Gas Piston System- M92 Black