Here's the answer

May 10, 2020   photos  

It is primary (insulator )(incoming or input)and secondary (insulator)(outgoing or output).  Primary and secondary bushings or HV and LV bushing.  This is a transformer and above of it have input and output of connection , and under of all this have isolators.
Incoming and outgoing bushings of Distribution transformer. This is Primary and secondary bushing. In general, Primary & secondary bushes. Input and output connected.