Slings are useful for making it easier to carry your rifle. These are 1 point slings with bungee retention. 1 point slings are meant to be mounted above or around the pistol grip of your rifle or SMG. If you do not have a sling mount around your pistol grip, you may want to consider a 2 point sling or a 1 point sling mount. 
One point slings are good for close combat. They allow a very free range of movement for the rifle and let your rifle freely sway when not in use. They are pretty much strictly a combat sling.