This feels like a good quality product.
Uses standard size spade connectors on the back for all the connections. Each is numbered with the common having a + sign next to it.
I like a rotary switch to be square so it is easy to stop it spinning. There is no need to over tighten the thread to hold it in place.
The rotating shaft is octagonal and made of a nylon like material. The cap is clipped on to a groove giving a very secure feel but requiring minimal effort to fit and remove.