Details
New old stock 9 pin miniature twin triode. Various brands. A long life, low microphonic 12AY7. The 6072A has a "computer-rated" cathode and higher leakage resistance between the elements.
NSN/FSN = 5960002620215, 5960005048547, 5960005534498, 5960008923809 (6072A)
HP/Agilent Number = 1932-0040 (6072A)