These are brand new JollyAirsoft Lightweight Wolverine MTW (or standard M4 spec) outer barrels, made with real 3K carbon fiber, 3D Printed base, and 6060 CNCed Aluminum threads.  M4 spec fits most brands on the market including G&G, VFC, Krytac, CYMA, etc. These will fit ANY MTW variant. We have tested Gen 1, Gen 2, Gen 3, 9, 308, and Article 1. If yours comes with a metal ring (mostly applies to the 308 and gen 3s) around the outer barrel for fitment, we recommend using that ring. If you don't have it for any reason, don't worry, we include a similar adapter! For the 10.3 variant, it saves about 4.5 ounces. Even more weight savings with longer barrels! In case you're looking for that perfect fit, you can see how the barrel is measured in one photo, we measure from where the receiver ends to the end of the threads. This is the standard way to measure airsoft barrels by most companies.  Every length in stock and ready to ship! $50 - 5in $50 - 6in $55 - 7in (208mm) $55 - 8in $60 - 9in $65 - 10.3in (285mm inner) $70 - 12.5in $75 - 14.5in - (380mm inner)  $80 - 16in (minimum AMS DMR Length, perfect for the .308) $85 - 18in Prices include extra $5 for hopup fees! If you click buy now, you will receive a 5in MTW Model. I'm happy to setup a listing for different lengths, just message me if you're interested! I will not trade or part out. Please be respectful of my time. You wouldn't ask Amped Airsoft if they do trades, this is no different. It is being listed as brand new, unless otherwise stated, for my online shop, JollyAirsoft.