Details
New old stock 9 pin miniature pentode. Various brands. E180F is the European designation.
NSN/FSN = 5960000196637, 5960005427107 (6688A), 5960007124031 (6688A), 5960007729062 (6688A), 5960008007581 (6688A), 5960008208717, 5960008331384, 5960008940128, 5960009027948, 5960009444042, 5960011676880
HP/Agilent Number = 1923-0041
Tektronix Number = 154-0215-00