This part is a kind of semiconductor called SBT20100CT.

Function of this product has SCHOTTKY BARRIER RECTIFIERS.

Manufacturers : Pan Jit International

Image and pinout :

Some of the text within the PDF file :

PSBT20100CT SCHOTTKY BARRIER RECTIFIERS Voltage 100 V Current 20 A Features  Plastic package has Underwriters Laboratory Flammability Classification 94V-O. Flame Retardant Epoxy Molding Compound.  High surge capacity.  For use in low voltage, high frequency inverters free wheeling, and polarlity protection applications  Lead free in compliance with EU RoHS 2011/65/EU directive. Mechanical Data  Case: Molded plastic, TO-220AB  Terminals: Axial leads,solderable per MIL-STD-750, Method 2026  Approx. Weight: 0.067 ounces, 1.89 grams  Marking: Part number 0.419(10.66) 0.387(9.85) 0.156(3.95) 0.147(3.75) 0.058(1.47) 0.042(1.07) 0.038(0.96) 0.019(0.50) 0.100(2.54) 0.100(2.54) 0.177(4.5) MAX. 0.50(12.7)MIN. 0.624(15.87) 0.548(13.93) 0.146(3.7) 0.130(3.3) 0.19 [ ... ]

SBT20100CT PDF Datasheet Download