AMAZING. Yup, that is basically the part that I created with the tubing. I bought mine "well used" and that particular part (along with many others) was missing.
I finally have mine shooting and I plan on using it this weekend for the first time at a scenario down in Commerce, GA.
Wish me luck, I am really excited about my little project MAG. I think I am hooked and I haven't even tried the LVL 10 or XMAG yet so I have opportunities to get even more addicted it seems.