This part is a kind of semiconductor called HER208.

Function of this product has 2.0 Amp High Efficient Rectifiers 50 to 1000 Volts.

Manufacturers : Micro Commercial Components

Image and pinout :

Some of the text within the PDF file :

MCC Features • • • • High Surge Current Capability High Reliability Low Forward Voltage Drop High Current Capability
  omponents 21201 Itasca Street Chatsworth    !"# $ %    !"# HER201 THRU HER208 2.0 Amp High Efficient Rectifiers 50 to 1000 Volts DO-15 • • • Maximum Ratings Operating Temperature: -55 °C to +125°C Storage Temperature: -55°C to +150°C For capacitive load, derate current by 20% MCC Device Maximum Maximum Catalog Marking Recurrent RMS Number Peak Reverse Voltage Voltage HER201 --50V 35V HER202 --100V 70V HER203 --200V 140V HER204 --300V 210V HER205 --400V 280V HER206 --600V 420V HER207 --800V 560V HER208 --1000V 700V Maximum DC Blocking Voltage 50V 100V 200V 300V 400V 600V 800V 1000V D A Cathode M [ ... ]

HER208 PDF Datasheet Download