That is a 6-50 outlet. What did you ask him to install?
It is similar to the more popular 14-50 but does not have a neutral wire, that's why there is one less hole.
It is totally fine for charging at up to 50 amps assuming the correct wire and breaker were installed.
Just be sure to order the 6-50 adapter on this page, not the 14-50.
Use a variety of household outlets to charge your Tesla with a Gen 2 NEMA Adapter. Simply attach the appropriate adapter to your Mobile Connector, plug into the corresponding outlet and begin charging. Adapter Max Distance Gained Per Hour of Charge Model S Model 3 Model X Model Y 5-15 3...
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