In addition, there's a forward loop the shooter can use if there's time to "sling up." This loop system solves a problem that exists with nearly every other type of shooting sling out there—namely, that no matter how tight you make the loop, it eventually slides down your biceps, compromising the shooting position. The locking tab, once tightened, keeps the sling in place.
This sling is tremendously versatile. I use it on my heavy precision rifles, my hunting rigs, and my AR-type carbines. ($130; riflesonly.com)