Mid Length Distributor Piston System- Along with our system this package Contains our 1 piece bolt carrier, handguards and handguard cap.
The Adams Arms Gas Piston System is an end user installed after-market product for Mil-Spec ARs. It will fit on any AR barrel with a .750" or 3/4" diameter at the shoulder where the front sight base sits. The Midlength version will work on barrel lengths from 16" to 18" that has an exsisting midlength gas system.