BCM 14.5 1/8 Twist ELW  MCMR 13 MLOK (Pinned BCM COMP) making it 16" OAL.

Features:

M4 Feed Ramp Barrel Extension
M4 Feed Ramp Flat Top Receiver
T-Marked Upper Receivers
USGI 1/8 Twist Rates
USGI 5.56 NATO Chambers
Mil-Spec 11595E - Certified Barrel Steel (CMV)
Chrome Lined Bore and Chamber
Manganese Phosphate Barrel Finish
ELW Profiled Barrel
HPT (High Pressure Test) Barrels
MPI (Magnetic Particle Inspected) Barrels
Barrel Length: 14.5 (Button Rifled) ELW
Rail: MCMR 13"