The UNIT4 M4A1-style training rifle is unmatched in size, weight, realism, and performance. The system combines the realism of a live rifle with the freedom to train anywhere. You get durable aircraft-grade aluminum construction and a durable handguard with Rail sections in the 12, 3, 6, and 9 O'Clock positions, just like the standard live M4A1. The UNIT4 M4A1 USG combines a Heavy Duty 14.5-inch outer barrel and a smooth bore inner barrel. This setup gives you a great baseline to build your training setup on. The UNIT4 Rifle has been purpose-built to provide safe and realistic firearms training in any environment. Train At Home: The UNIT4 is the ultimate training enabler, allowing users to practice basic marksmanship, train new shooters or engage in force-on-force scenarios in their home, garage, basement or yard. Feels Like Your Real AR: The UNIT4 has the same fit, form, function and fidelity as a live AR, including realistic recoil. It is compatible with off-the-shelf AR accessories, so you can set up a true 1:1 trainer with the same touchpoints as your live AR. 100% Safe Platform: The UNIT4 is a dedicated training platform, has been classified as a non-firearm by the ATF and cannot chamber a live round. It can be safely used with eye protection and ships via normal mail straight to your home without an FFL. Built To Last: Upper and lower receivers forged from aluminum. Real steel internals made in USA with same materials and processes built into live ARs. Our magazines can be dropped onto any surface. All UNIT4 Rifles and Magazines are protected by our industry-leading 5-Year Warranty. MATERIALS & CONSTRUCTION: Lower Receiver Mil-Spec with Rear Receiver QD Swivel Attachment Point. CNC Machined of 7075-T6 Aluminum, Type III Hard Coat Anodized Upper Reciever Mil-Spec with Indexing Marks. CNC Machined of 7075-T6 Aluminum, Type III Hard Coat Anodized Barrel (Outer & Inner) Outer: Chrome Moly Vanadium Steel, Mil-Spec Heavy Phosphate Coated.Inner: Nickel plated, smooth bore, brass tube for 8mm Rounds Muzzle Device Standard Mil-Spec A2 Flash Suppressor, Cerakote Blue Bolt Carrier Group 4140 Low Alloy Steel; Minimal Changes to M16 Profile while allowing for Non-Firearm Certification Sights Magpul MBUS 3 Rear Sight; A Frame Front Sight Handguard Leapers AR15 Drop-in Quad Rail Handguard, Carbine-length Charging Handle Mil Spec with Right Latch Selector Ambidexterous; Safe, semi & full Receiver Extension 6 Position Mil-Spec 7075-T6 Aluminum Buttstock Mil-Spec GI Stock Pistol Grip Standard A1 GI Grip SPECIFICATIONS: Caliber 8mm Muzzle Thread 5/8" x 24 TPI (Threads Per Inch) Gas System CO2 Barrel Length 14.5" Magazine UNIT4 Magazine Manufacturer UNIT Solutions