The first residential ones I put in were 6-50r GE models. They seem to be fairly durable, because I know of one that’s been in service for at least 10 years now. After a few years I was seeing some 14-50’s, but most 40 amp I put in were commercial hard wired. Eaton required a neutral because they didn’t make a dual volt rated 208-240 volt coil contactor, so they used a 120 volt coil to be universal. The last one I put in used a 14-50, but could have been ordered as a 6-50. Cost the doctor an extra $75 in wire that he didn’t need, but if you can afford to throw money away on an EV, $75 is nothing! LOL!