I need to replace an ITT T80 vertical model. What can I replace it with?

Thanks.

That's pretty old! Mercury? 2 wire? Heat only or heat and air? Some of the older millivolt units require transformer change to 24vac

Two (2) wire; bi-metal, 750 mv

If you Google "750 millivolt thermostat", you will find compatible models. They are heat only. That is why I asked if 2 wire.

Thanks so much.