Pair of International Service Master 6JF6 vacuum tubes made in Japan  
Tested with a calibrated TV-7D/U tube tester.
Calibration by Daniel Nelson.
Tested at: 98 102
Average new:100
Minimum good: 54 
The minimum is equal to 65% of the life of the tube.
Tested for shorts and gas.
Date code: 922-450
NOS/Used: new 
Construction: copper rods gray plate dual round getters
Glass: clear
Base: -
30-day free return.
We combine shipping $1.00 for each extra tube purchase.
Your items will be packed very well and shipped promptly.
Always glad to answer any questions.
Thanks for looking!