5AR4 Amperex Bugle Boy Fat Base Tube 1961 Blackburn factory etched code f32 B1K2

Dual halo top getters

Tested as new on a restored/calibrated Hickok 539B tube tester.

The etched codes are visible looking carefully, however wasn't able to capture them in the photos are they are faint.

The silvering on the tube dome is uniform without any variations, however its not possible to photograph of to show this.

153/149 are the values, whereas 55/55 are the minimum acceptable.