It's a copy of the Z-Aim sling.
Yes they do work well if you set them up correctly and work much better if the rifle has the sling mounts on the side rather than underneath.
I've made my own versions at home as I don't like the fact their chest strap connects to a separate piece of webbing that isnt completely attached to the main sling. Also the chest strap is rarely long enough to be versatile to use with extra padded clothing or a rucksack, unless you run it under the rucksack but then it gets caught.