I used this for AMP MetriMate connectors. was great. Although I did come across a couple of pins that even an AMP/Tyco branded pin couldn't figure out. The trick I found for this pen and AMP/Tyco is that you have to lower the tool all the way down and then rotate and press the pen. Pistons. It's a little weird at first, but it's the best way to ensure all teeth are tight before pushing. If you push and they're not compressed, you can bend them in plastic and they'll never come out. The only major difference is that the Jonard case is slightly thinner than the AMP/Tyco. Time will tell if this affects my connections.