This part is a kind of semiconductor called 1N3031B.
Function of this product has Silicon 1 WATT Zener Diodes.
Manufacturers : Microsemi Corporation
Image and pinout :

Some of the text within the PDF file :
1N3016B thru 1N3051B 1 WATT METAL CASE ZENER DIODES SCOTTSDALE DIVISION DESCRIPTION This well established zener diode series for the 1N3016 thru 1N3051 JEDEC registration in the metal case DO-13 package provides a glass hermetic seal for 6.8 to 200 volts. It is also well suited for high-reliability applications where it is available in JAN, JANTX, and JANTXV military qualifications. Lower voltages are also available in the 1N3821 thru 1N3830 series (3.3 V to 7.5 V) in the same package (see separate data sheet). Microsemi also offers numerous other Zener diode products for a variety of other packages including surface mount. APPEARANCE WWW . Microsemi . C OM DO-13 IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com FEATURES • • • • Zene [ ... ]
1N3031B PDF Datasheet Download
