The MK1 MOD 1-M line, revamped for 2018, features the PWS long stroke piston system. Internally, this line offers the tried and true system that PWS owners have grown to know and love. Featuring a free-float MLOK handguard, forward assist controls, and a more true to mil-spec design, the MK1 MOD 1-M line is a go-to for not only civilians, but also Law Enforcement. With the fully forged upper and lower receivers, the MK1 MOD 1-M is a no-nonsense tool for when you need a high value option that is relentless and unstoppable. The shortest available option in the MK1 MOD 1-M series, the MK107 was the first firearm developed by PWS. Known as "The Diablo", the MK107 was designed to replace MP5 style weapons. Used heavily in law enforcement and SWAT settings, the MK107 has been a vital part in the growing use of SBRs as patrol rifles. Barrel Length: 7.75" Caliber: .223 Wylde Weight: 3 lb. 8 oz. Length: 17" Piston System: Pistol PWS long stroke piston operating system 3-setting adjustable gas system