This part is a kind of semiconductor called CR2032.

Function of this product has Lithium / Manganese Dioxide (Li/MnO2 ).

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

EVEREADY BATTERY CO. Internet: www.energizer.com 1-800-383-7323 / USA/ USA 1-800-383-7323 1-800-383-7323 / CANADA 1-800-383-7323 / CANADA + 44 (0) 208 920 2306 / EUROPE ENERGIZER NO. CR2032 Chemical System: Lithium / Manganese Dioxide (Li/MnO2 ) Designation: Battery Voltage: Average Weight: Volume: Average Capacity: Maximum Reverse Charge Current: Energy Density: ANSI / NEDA-5004LC, IEC-CR2032 3.0 Volts 3.3 grams (0.12 oz.) 1.0 cubic centimeters (0.06 cubic inch) 225 mAh to 2.0 volts (Rated at 10k ohms continuous at 21ºC) 1 microampere 198 milliwatt hr/g, 653 milliwatt hr/cc Industry Standard Dimensions in mm (inches) TYPICAL DISCHARGE CURVE Simulated Test @ 21ºC (70ºF) 3.2 Closed Circuit Voltage 3.0 2.8 2.6 2.4 2.2 2.0 1.8 0 400 800 1200 1600 2000 2400 Service, Hours Simulated Appl [ ... ]

CR2032 PDF Datasheet Download