Hi guys, I'm the one who designed it. The wedge angle is at 13 degrees to make the two mags, Lar-15, look similar to the blocked 30rds mags. It is called " P.P. Coupler." P.P. stand for patent pending. Yes, it is CNC milled from aircraft aluminum. As for the price, the Samson Mac couplers is also CNC milled but cost is $59.99! It only couples a total of 10 rounds from the blocked 30rd mags, sad. I have future plans to put two, yes, two P.P.C. together with a total number of 40 rds. attached to you favorite toy, legally. I do recommend if you were to drop the mag out in the heat of a tac shoot that you bounce it off you leg from preventing the lip from being damage. It is not hard to do, nothing is fault free. I sure some of you will like it, some will criticize it. You can't please everybody. For anyone that bought one, please let me know what you think about it, thanks for purchasing it and please tell your friend about it.