It's an "Outdoor Connection" brand. The brown one was a presumably used scratch 'n dent I picked up for $1. Missing a Chicago screw when purchased, the one I replaced it with works flawlessly, but isn't an exact match.
I know nothing about "Outdoor Connection".
I have what I take to be a later one in black, which I apparently bought new. It has a label, the center loop is nylon vs. the metal on the brown one.
EMail me, I'd be happy to send you either one. Your choice of brown with slight wabi-sabi, or a newish black one.
Honestly, they don't work any better than the generic AR15/M16 nylon sling, though. Those very simple babboos are 3 pieces, i.e 1 sling, and 2 metal sliders. THAT is a near perfect bit of gear, simple and 100% effective.
(EDIT)
Just looked for the slings online.
"Outdoor Connection" apparently no longer makes the brown one. They still make what I think is the same black sling as mine. And inevitably camo ones.