This listing is for a single NOS 6BK7 tube with black plates by Sylvania.
We Guarantee this tube to test new with no gas or shorts using.
(Hickok Standard Measurements) Or your money back including shipping cost.
Our vacuum tubes sold on eBay come with a 1-year replacement Warranty for defects/failures.
You must return the tube for warranty service; we pay return shipping.
Test procedure
We have bogie/reference tubes for all numbers we sell.
Reference tube is tested first then the tube listed for sale.
This assures the tube you will receive meets industry standards for a new vacuum tube.
Our Hickok testers are calibrated monthly to assure accurate test results.