Sorry this is not some new item. Brent shared this item on his Instagram the other day. The FCG is the match one Colt made for use in the Colt Accurized Rifle HBAR Elite. They called it the low mass trigger system. And it works pretty damn good.
You can see how the hammer was modified to make it lighter for faster lock time, It also came with lighter springs and a plating for smoother action.
It’s rare to see them sold like this. But, you could run across them up till about 2007. I don’t think they still offered it as an upgrade spare part that late, I just saw some trickle out around that time. Normally the only way to encounter these was to buy the 6724 rifle. Now discontinued I believe.
I should note that if you do find them like this, remember they will onyl fir the older large hole trigger pins.