Arcturus type 127 / 27 Blue Bulb Engraved Etched base Vacuum Tube Hickok 539B

Test Results on the 539B are 1400 where 630 is minimum (meter on 15000 range scale per requirements) 

I cannot guarantee the tube as it is over 70 years old. 

I cannot guarantee that this tube will work flawlessly in your application. 

I cannot guarantee that this tube will test similarly in other testers as they all test with different parameters

I can only provide the pictures and the test results I have. you get what you see. No returns, no refunds.