(!!!) (Best Pair) 6203 GE NOS 1976-1979 (53-54/40 and 54-54/40) Title: 6203 GE

1 pair) 6203 GE NOS 1976-1979

1 tube) 54-54/40

1 tube) 53-54/40

6203 is a ruggedized 6X4 with 9 pins, a 6X4 has 7 pins

6203 heater current is 900ma, 6X4 heater current is 600ma