National UY-57S Vacuum Tube

Matsushita UY-57S vacuum tube, 5-pin connection.

- Brand: National
- Model: UY-57S
- Manufacturer: Matsushita Electric Ind. Co., Ltd.
- Number of pins: 5
- Type: Vacuum tube

I don't believe it has been used.
I have confirmed continuity of the heater. The box has tears.

Thank you for looking.