Mullard  
6BN8 
Vacuum Tube

Made in UK 

Tube was tested on a Hickok 752A Mutual Conductance Tube Tester and GUARANTEED WORKING and reads above the minimal acceptable Mutual Conductance value listed on the tube tester chart. . 

Tubes are tested for Shorts, Gas, and each section tested for Mutual Conductance, (Gm) 

Tubes was pulled from a Heathkit SB-610 Monitor Scope.  Was working correctly in the scope.