The M4-SBR-L is Franklin Armory's upgraded AR15 offering with a factory-installed BFSIII™ binary trigger and Franklin Armory Triumvir™ muzzle device pinned & welded onto the rifle's 14.5" barrel.   SPECIFICATIONS: Barrel Length + Type  14.5" M4 Contour  Handguard/Upper  15" FSR™  Sights  N/A (Optics Ready)  Twist  1:7 RH  Charging Handle  Standard  Bolt Carrier  Salt Bath Nitride  Lower  Libertas™  Trigger  AR-C1 BFSIII™    Gas System  Midlength  Gas Block  Low Profile  Muzzle Device  Triumvir Pinned & Welded™   Color  BLK  Stock  Magpul CTR  Features  Billateral Push-button QD sling mounts  Grip  Ergo Ambi Sure   Calibers  5.56 NATO   BFSIII™ is NOT for civilian sales in CA, DC, IA, NJ, NY, HI, DE, RI, FL, MD, CT, or WA.   Pinned & Welded Triumvir™ muzzle device information: The Triumvir™ muzzle device is a strategic combination of design features to better equip users of modern carbines employed in defense and CQB roles.As a flash hider, there are three custom venturi cuts that all but eliminate the flash signature, even in short barrel configurations!The unique venturis are machined shorter on the bottom and longer on the top. The shorter, venturi cuts allow for a reduced dust signature when shooting prone. The longer cut on top generates a compensating effect which results in a greater ability to stay on target and reduce felt recoil.Additionally, the Triumvir™ is a high efficient linear compensator. It is designed to propel the report of the muzzle forward toward the target. Consequently, the operator will perceive a greatly reduced report. Even those standing either side of the operator, behind the plane of the muzzle, will find the peripheral report is greatly reduced. Fellow shooters at the range will appreciate the result.