This part is a kind of semiconductor called TAA550.

Function of this product has Linear Integrated Circuit.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

The TAA550 is a monolithic integrated voltage stabilizer in a TO-18 two pins metal case. It is especially designed as voltage supplier for varicap diodes in television tuners. [ ... ]

TAA550 PDF Datasheet Download