Sylvania 5881 / 6L6WGB Beam Power Tube Power/Output. NIB USA.
5881 =6L6WGB. Beam Power Tube Power/Output. Tube type Octal (Int.Octal, IO) K8A, USA 1935.
2- RCA 5881 6L6 Vacuum Tubes Tested Gray Plate
Gray Plate, Side "O" Getter. Tube-1 Gm 6380 - 76.8mA.