This part is a kind of semiconductor called 1403.

Function of this product has Bulk Metal Foil Technology 4 Pin Transistor Outline Hermetic Resistor Network.

Manufacturers : Vishay Siliconix

Image and pinout :

Some of the text within the PDF file :

1403 Vishay Foil Resistors Bulk Metal® Foil Technology 4 Pin Transistor Outline Hermetic Resistor Network The four pin TO-18 package is the smallest available in the miniature hermetically sealed series of networks. It should be the first choice for simple networks requiring multiple R's. This network can contain up to 5, V5X5 resistor chips. Note that case grounding limits the circuit options to a two resistor divider. Review data sheet “7 Technical Reasons to Specify Bulk Metal® Foil Resistor Networks.” Product may not be to scale ORDERING INFORMATION - 1403 PARTS Networks are built to your requirements. Send your schematic and electrical requirements to the Applications Engineering Department. (See data sheet “Network Worksheet.”) A unique part number will be assigned which [ ... ]

1403 PDF Datasheet Download