Limited Edition from DoingArts Studios (dnA) Quality, Authentic Design for Airsofters and Collectors Faithful Replication of the Mk 18 Mod 1 14.5-inch Navy Variant Independent 1400**** Serial Number on Receiver with Laser White Strike-Through for the M4A1 CARBINE and Stamped Navy 18-1 Rollmarks 14.5-inch M4 Profile Steel Outer Barrel with Lightened Steel Gas Tube Steel SF 4 Prong Flash Hider (1/2-28 inch RH Threading), Sight Base, Front Sight, Forward Assist Button, Dust Cover, Selector, Bolt Catch, Magazine Release and such CNC Aluminum 13.5-inch G-Style SMR Mk16 Handguard, Steel CQD Sling Mount, KAC300 Style Iron Sights and Gen 1 Crane Style Stock Real Steel Spec. Handguard, Buffer Extension Thread and Grip Installation Structure VFC M4 GBB System Base Heavy Felt Recoil with VFC Performance VFC v3 Nozzle with NPAS and v2 Valve Knocker Set VFC v2 Mag Compatible Only 6061-T6 CNC Aluminum Construct with Steel Internals Two Tone Finish - Black Base with Flat Dark Earth Rail This product is only compatible with gas designed specifically for Airsoft guns. Do not use lighter fluid or butane gas, as that will cause permanent damage.