PWS (Primary Weapons Systems) MK107 MOD 2-M in 223 Wylde (will also shoot .223 and .556) AR-15 Adjustable Piston Complete Upper. This is in Mint condition. I am the original owner and fired very little. It is accurate and completely reliable. I am downsizing my collection. The 3-position adjustable gas piston makes it perfect for suppressing. $800 Cash. Buyer must be at least 21 years of age. Please call or text David at 208.786.2005. I live in Boise.