Lot of three National 807 vacuum tube tested strong 
Tested with a calibrated TV-7D/U tube tester.
Calibration by Daniel Nelson.

Tested at: 80 64 87 

Average new: 74

Minimum good: 48 

The minimum is equal to 65% of the life of the tube.

Tested for shorts and gas.
Date code: -

Construction: two tubes are identical 

Glass: clear

Bases are tight

60-day free return.

We combine shipping $1.00 for each extra tube purchase.

Always glad to answer any questions.

Thanks for looking!

We ship using the best proven packing system for tubes. The tubes are wrapped in bubble wrap packed with  biodegradable peanuts in a new box. We have shipping thousands of tubes this way with almost no breakage for over 15 years