A bit disappointed with my industrial Hubbell L14-30, but still a fine connector
Disclaimer: I'm not a fan of connectors that don't have a very definite clamping of the power cord. I was somewhat disappointed to see Hubbell producing connectors of the "auto-grip" type, which the one I received is. I've always bought Hubbell because they're tough and easily mounted and re-used, and particularly because of their strong clamping of the cable.
Regardless, this one is of the quality I expect from Hubbell. I make sure each conductor is tightened-down and I've never had fractures or other problems with their conductor clamps (one of my nick-names is "Godzilla grip"). Only use will tell if this connector lives up to the high standards that Hubbell has set.
Regardless, I expect that the gland at the cable entry to the connector will effectively exclude liquids and fine particles - both important attributes in industrial and ad-hoc settings.
I got these connectors to build power cables for some amplifier equipment racks. They are the older style Hubbell connectors, but look brand new. If you are looking for durable connectors at a reasonable price, used/reconditioned is the way to go!