Details
New old stock 7 pin miniature remote cutoff pentode. Various brands. Type 6662 is selected for mobile service (steady output at 6.3V +/- 1.3V on the filament).
NSN/FSN = 5960001886589, 5960005534524 (6BJ6A), 5960005776186 (6BJ6A), 5960006178600, 5960006858999 (6662)