Philips PT9 directly heated triode

The valve measures 114x48mm overall and has a 4-pin base.

The top of the envelope has the number 10761, and the label on the side reads:
Ministero Delle Finanze
Nota No.
149407
17 ? 1959
Eso ?? ssa Radio - "esonero tassa radio" - this means that the valve was not subject to government radio tax, presumably having been supplied to a government agency, state broadcaster or postal service.