Adams Arms didn't invent the AR15, we just made it better. By utilizing our patented piston system, hot carbon and gas do not come in contact with critical moving parts and components. This results in much less maintenance and fewer malfunctions than the standard AR platform. The Adams Arms Piston System provides superior performance and has lower maintenance costs than anything available on the market today. The Retro-fit System offered by Adams Arms saves Law Enforcement, Military and Private Citizens thousands of dollars by offering a simple upgrade option, instead of the high cost of replacing their current firearms.