This is a NCSTAR Sling known as the Single Point Sling, model AARS1PT.
Single point sling designed for fast attachment and removal. The Single point is great for a primary rifle for full mobility but retains weapon if the need arises to transition to your secondary.
Features:
Heavy Duty Fully Adjustable Single Point Sling
Heavy Duty Bungee Cord for Complete Comfort and Stability
