What kind of plug terminal is this?

[bookem666]

After taking a cursory glance at the power supply plug on my 1964 Streamline I assumed that it was a standard NEMA tt-30 style plug and so I went to the hardware store and bought an adapter.

When I got home I quickly discovered that my trailer had a slightly different style of plug (see picture). What exactly have I got here?

[bwoodtx]

Looks like a 50amp service plug.

[bookem666]

Thanks. That helped me figure it to be NEMA 10-50.

No luck so far in finding an adapter.

[bwoodtx]

You won't fond an adapter-that will only plug into a 50amp service outlet. Ck and see if your trailer is set up for 50amps. One of the breakers in the breaker box should be 50amp if it is.