We love the simplicity, durability, and field repairability of simply tying your sling to your rifle with a length of paracord. But when using our PQD, we wanted a way to contain the knot at the sling. The Smith Loop, by 1350 Mill Works, is simply a polished-version of the paracord loop that retains the knot inside of an aluminum sleeve. Instead of Paracord, we've opted for a 450 lb tensile strength bump cord whose slightly smaller diameter allows smoother operation in and out of the PQD. The addition of rubber retainer sleeve allows you to cinch down the loop ensuring it stays put.We recommend the 3" variant for PQD, whereas the 4", 6", and 8" are great for a variety of attachment points. The Smith Loops have been strength tested by Nick at 1350 Mill Works and can sustain his weight of 170 pounds for 3-4 pull ups (using two Smith Loops simultaneously)