This part is a kind of semiconductor called SB340.

Function of this product has MEDIUM CURRENT SCHOTTKY BARRIER RECTIFIER.

Manufacturers : General Semiconductor

Image and pinout :

Some of the text within the PDF file :

SB320 THRU SB360 MEDIUM CURRENT SCHOTTKY BARRIER RECTIFIER Reverse Voltage - 20 to 60 Volts DO-201AD Forward Current - 3.0 Amperes FEATURES ♦ Plastic package has Underwriters Laboratory Flammability Classification 94V-0 ♦ Metal to silicon rectifier, majority carrier conduction ♦ Low power loss, high efficiency ♦ High current capability, low VF ♦ High surge capacity ♦ Epitaxial construction ♦ Guardring for transient protection ♦ For use in low voltage, high frequency inverters, free wheeling, and polarity protection applications ♦ High temperature soldering guaranteed: 250°C/10 seconds, 0.375" (9.5mm) lead length, 5 lbs. (2.3 kg) tension 1.0 (25.4) MIN. 0.210 (5.3) 0.190 (4.8) DIA. 0.375 (9.5) 0.285 (7.2) 0.052 (1.32) 0.048 (1.22) DIA. 1.0 (25.4) MIN. MECHANICAL DATA [ ... ]

SB340 PDF Datasheet Download