The M4E1-SD is a collaboration project between Aero Precision, SilencerCo and Ballistic Advantage. This .223 Wylde dedicated suppressed upper receiver is the first of it’s kind in the Aero Precision lineup and has been fine tuned to our standards, resulting in a premium quality, high performance upper assembly.Includes:Aero Precision M4E1 Enhanced Upper Receiver with custom designation and M4E1-SD engraving.Ballistic Advantage BA Hanson 10.5″ .223 Wylde Barrel. Features a gas port that is drilled to allow for dedicated suppressed use and pinned low profile gas block.SilencerCo Omega .30 Caliber Silencer. The Omega is rated for everything from 5.7mm to .300 Win Mag and is the shortest, lightest, quietest, most versatile silencer from SilencerCo. Made from titanium, stainless steel and Stellite(TM). This version comes with the 5/8×24 direct thread mount and flat endcap, but it will work with all SilencerCO Omega accessories.12″ and 15″ Enhanced Handguard of choice, allowing for use of accessories around the suppressor.This complete upper does not include BCG or Charging Handle. These products may be selected as add-ons under the Finish Your Build tab.Please NoteThis is an NFA Item. Please contact your FFL/SOT and confirm they will accept this item before placing your order. The wait time for approval to transfer this item to an FFL/SOT dealer is 4 – 8 weeks. The wait time for Form 4 approval (FFL/SOT dealer transfer to customer) is approximately 8 months.For more information on purchasing a suppressor, check out the SilencerCo education page.There will be a 20% cancellation fee applied to any orders canceled during the application process.