This is a SB Tactical Stabilizing Brace known as the SB Mini, model SBMINI-01-SB.
The SB-MINI is the lightest" minimalist interpretation of the Pistol Stabilizing Brace. When weight and total footprint are a consideration" the SB-MINI is the solution. Fits AR rifles.
Features:
Fits AR rifles
Includes brace and adjustable nylon strap
Diameter compatibility 1.2-1.25