Oh yeah! I did want to mention that the tether kit I ordered from them is kind of expensive at $24.95. I mean, it's just a small nylon strap that hooks to the camera strap eyelet, then to the sling's D ring. I guess they felt kind of bad about charging that much, because they included a couple of D rings with it. I mean, they're nice D rings, but I don't need 2 more D rings. lol
ETA: thinking about it, I guess you can use the D rings to hook to your belt loop or further up the sling strap, if that is what some users do. Then the extra D rings would be needed.