The 845W is a general purpose, 100 watt, triode with a mu of 5.3 that was designed to be an audio amplifier tube. This tube is a variation of the 845 and was only made by United and it was equipped with an additional plate support pin. United originally designated their tubes 945 and this number is written on the insulation inside the tube. The "W" designation indicates the tube is "Warized" and ruggedized to meet JAN-1A specifications.
Length = 7.87" Diameter = 2.31"
Max voltage = 1250
Max current = 150
Fil voltage = 10
Fil current = 3.25