Looks like the Indian Creek Black Diamond Choke. I used one the other day and I was very impressed to say the least. It takes a lot for me to be impressed with a choke shell combo anymore, but this one with Win. Extendeds really performed exceptionally well.
Once I saw it perform next to my Jellyhead, so am I! I am just not quite willing to give up yet on what I think is an ultimate pattern for me. I get a super even and filled pattern at 50 yds. It isn't the tightest pattern, but it is the most even pattern I have ever achieved. It consistently puts between 3-7 pellets in the brain/spine at 50 yds, but I'm getting enough spread to cover up any minor mistakes in aiming and/or the turkey moving.
That IC choke did just about as good, but gave a more concentrated pattern at 40yds.