You are correct. I just looked at them side by side. Not sure what I was thinking. I did try another brand, before the Hahn and it failed, big time. It looked more like the Colt with the flat feed ramp, so maybe that's where I got confused. It had some set screws to hold it in place, but it worked itself loose before I could finish one magazine. I tried thread locker and tightened it so tight that it marred up the mag well of the lower. It still wouldn't stay put. The Hahn that I have was very tight and has a roller on the front of it to keep tension. Once it is in, it does not move at all. The bolt catch arm on the Colt is very long. On the Hahn, it uses the normal bolt catch and the adapter itself catches the mag follower and then pushes the factory bolt catch. I had a lot of trouble with the first block, so I may have tried to get the alignment perfect when putting in the Hahn. Not sure, but I was certainly sold and bought another one for another gun. I took a couple of pics, but forgot that I no longer have photobucket...