There is another version that is screw tightened, but I prefer the quick detach. Note that this is too long to properly mount on the bottom rail, it'll touch the bottle slightly, and I won't risk damaging it. You'll need to mount this on the left side of the Impact.
Easy to attach a sling to this stud. The other part can go to the butt, or you can add a longer screw or stud to attach it. Either way, the Impact isn't too sling friendly.