These are single point, bungee slings by NCStar.
 
Single point sling designed for fast attachment and removal. Single point is great for a primary rifle for full mobility but retains weapon if the need arise to transition to secondary
Heavy Duty, Fully Adjustable, Single Point Sling
Heavy Duty Bungee Cord for Complete Comfort and Stability
Single Point Clamp Attachment will fit AR Style Single Point Yoke Rings