I was checking out the various lines offered by Vista Outdoor when I saw this fixture on a sling in the Blackhawk section. It reminded me of a frame surrounding a Red Dot Sight.
Turns out, it’s the rapid adjust slider for their Multipoint Sling. Although it’s fixed in an open position, it’s soft enough to collapse when you need it to.
The webbing material is offered in slick, padded and stretch variants in Coyote and Black. The sling is Berry compliant and offered in multiple mounting configurations including QD, HK hooks and free ends with no attachment, allowing you to use your own parts. But, my favorite feature is that they’ve included a two-point to single-point adapter on the models fitted with QDs.
blackhawk.com/products/long-gun-accessories/long-gun-accessories/tactical-slings
