Pro-C A/C for R-134A Refrigerant, ACP400AD

Two main flaws with the one that I received. First off, and most importantly, the quick connect did not seal around the A/C service port. That was noticed right away, after connecting it to see how much pressure the system had. Loved the digital display, and I have every reason to believe that it was accurate. Next, piercing the can with the finger lever was nearly impossible. It just didn't extend far enough, really. After a few attempts of removing the can and reattaching it, tighter each time, it finally pierced it. I was afraid I was tightening the can to the gauge to the point that the plastic gauge was going to break. Everything seemed good at that point, other than the small leak at the service port. The one can I used with this was essentially wasted as it boiled off/evaporated somewhere between the connection to the gauge and the service port. The pressure in the system was actually 7 psi lower after attempting to charge it with one can. Afterwards I used my old charging hose, and separate gauge, to add a can to the A/C system. I was hopeful that this new unit would save me the inconvenience of of switching between my charging hose and my gauge to see how much I've added to the system. There are other charging hose and analog gauge sets out there for the same price that have less plastic parts than this unit, and will likely do the job without leaking.