Lightly used Precision Armamaent EFAB Hybrid Muzzle Device. I have one on my 11.5" BCM and it works great on that. Designed for shorter barrels. 1/2x28 thread, and comes with their recommended Accuwasher kit. MSRP $175 total, my price shipped via USPS to lower 48 is $115. Will provide tracking number when shipped. Payment via personal check. Thx for looking!