What 240V outlet type do I need for a plug-in EVSE?

[JimSouCal]

Original poster here. If anyone's curious, what I finally did was hire an electrician to install a new 40A 240V line, and put an outlet on it.
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The total setup:
New 40A breaker, wiring, and 6-50 outlet: $450
Clipper Creek LCS-25: $545
6-50 plug: $15
Grand Total -- $1010

Solid move as I follow things. You can also let any Tesla Types do a charge too with adaptor...