This part is a kind of semiconductor called FR1205FCT.

Function of this product has 12A FAST RECOVERY RECTIFIERS.

Manufacturers : Frontier Electronics

Image and pinout :

Some of the text within the PDF file :

FR1205(F)CT THRU FR12100(F)CT SPECIFICATION Rev. A 12A FAST RECOVERY RECTIFIERS Fig 1. TO-220AB FOR FR12xxxCT PRODUCT FEATURES 1. FLAMMABILITY CLASSIFICATION 94V-0 2. LOW FORWARD VOLTAGE VF 3. FAST RECOVERY TIME 4. LOW THERMAL RESISTANCE/HIGH VOLTAGE 5. GLASS PASSIVATED CHIP JUNCTION 6. CASE: TRANSFER MOLDED TO-220AB FOR FR1205CT THRU FR12100CT ITO-220AB FOR FR1205FCT THRU FR12100FCT 7. DIMENSIONS IN INCHES AND (MILLIMETERS) 8. LEADS: SOLDERABILITY PER MIL-STD-202 METHOD 208 9. WEIGHT: 2.1 GRAMS (TO-220AB) 1.7 GRAMS (ITO-220AB) 10. RoHS COMPLIANT/HALOGEN FREE Fig 2. ITO-220AB FOR FR12xxxFCT ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS (TA =25°C UNLESS OTHERWISE NOTED ) AND ELECTRICAL CHARACTERISTICS RATING MAXIMUM AVERAGE FORWARD RECTIFIED CURRENT, SEE FIG.1 PEAK FORWARD SURGE CURRENT [ ... ]

FR1205FCT PDF Datasheet Download