This is all I know about the heaters.
They measure about 40 ohms which is not
going to give 380 watts, but they will
work. No manufacturers name. The leads
are braided. The '380' watters I bought a
year ago were about 100 ohms - uuugh, and
the leads are a flat metal strip.
Braided good, flat strip bad. Worship words.
I added a photo of the heater cover.
Wayne