ENGLAND This is an indirectly heated triode 4033L made in England.
I used to see them here and there in the 70's, but I haven't seen them much lately. You can make a power amplifier with good sound.
The base is also rounded and has a slightly modern look. It seems like the sound is really good.
This is a gem that is difficult to obtain.
It looks like NOS, but there are some letters that have disappeared due to being taken out of the box, so I am selling it as a used item in good condition.