See photos. I'm having trouble finding this on the internet. Looks like it's some kind of compression connector for EMT conduit, with dimples. The conduit is 3/4"
What is this style of connector called?
Is there an easy/right way to remove it?
Those are indenter type EMT fittings, they were popular in the 1960s. There was a special crimp tool that crimped that dimple into the fitting and pipe. They aren't commonly used but are still in the catalogs.
They are difficult to impossible to take off unless you can drill out all four dimples.