I am a master DIYer and bought it for home use to service a few cars. As mentioned, the cartridge was difficult to install properly, but after a little adjustment it mostly worked. I'm wondering if this is a quality control issue as not everyone seeing this has this issue. I bought it in July 2016 and a few months ago it stopped working as the pressure gauge was losing air and it was becoming increasingly difficult to engage the cartridge without leaking. I finally got to the reviews hoping to find someone with a similar issue who has a solution, but looks like this is going in the trash instead.