SIONICS Premium Edition Upper Receiver with 13.5" SIONICS M-LOK Rail. 

(Note: This is a standard length handguard, the XL has a 15" Rail and can be found HERE ) 

This is a complete upper with a NP3 BCG and Radian Raptor Charging Handle. 

• Upper Receiver: 7075 M4
• Barrel: 16”, 41V50, 5.56mm NATO Chamber, 1:8, Air-Gauged, Radiograph and MP Inspected
• Medium Contour Barrel
• Bolt Carrier Group: Sionics NP3 Full Auto M-16 BCG
• Bolts are all 100% HPT & MPI
• Bolt is Shot Peened
• Gas System: Mid-Length, Direct-Impingement
• Muzzle Device: A2 Flash Suppressor
• Hand Guard: Free-Float 13.5" SIONICS M-LOK Rail - Low Profile Gas Block