Details
Used old stock ruggedized octal beam power tube. Various brands. Some have black bases and some have brown bases, depending on the maker. These have lower ratings than 6L6GC tubes, but higher ratings than most of the rest of the 6L6 family. These are often used in Fender amplifiers.
NSN/FSN = 5960000988793, 5960001346838, 5960002393052, 5960002620161, 5960005534361, 5960005561277, 5960005781517, 5960006155641, 5960006173205, 5960006174917, 5960006179176, 5960009966898, 5960012087250