In discussions with reps it seems they are trying to put together a systems to reduce the recoil impulse as well as weight of the SCAR17 platform. Handl seems to be quite secretive about it though, so it's hard to see what the final result will be, and aside from that general statement and it's metal not polymer, I have no idea what it does for you.
Personally I don't see a need to have this product at this time, just to have a metal piece in place of what FN designed as a polymer piece. Same reason I don't see the need to have a metal lower or buttstock of any variety, make or model, regardless of who's name is scratched into the anodized aluminum on the product.
Regardless it is good to have a variety of aftermarket SCAR products even with the continual tea-fights, fanboys, and legal fights between manufacturers of said products, which is odd because it seems to only happen with the SCAR and not other weapon systems like the AR or Tavor.