This is a NOS Western Electric / RCA 6L6G Triode.
Looks like it was made by RCA Radiotron for Western Electric. See
markings on the box. Has original packing material. This was just
tested on a calibrated TV-7D/U. The 6L6 should test at least 23.
This tube tested 44. Excellent near mint condition for the tube.
Box is coming apart.