This part is a kind of semiconductor called D525.
Function of this product has 2SD525.
Manufacturers : Wing Shing Electronic
Image and pinout :
Some of the text within the PDF file :
2SD525 NPN EPITAXIAL SILICON TRANSISTOR LOW FREQUENCY POWER AMPLIFIER TO-220 Complement to 2SB595 ! ABSOLUTE MAXIMUM RATINGS (TA=25℃) Characteristic Collector-Base Voltage Collector-Emitter Voltage Emitter-Base voltage Collector Current (DC) Collector Dissipation (Tc=25℃) Junction Temperature Storage Temperature Symbol VCBO VCEO VEBO IC PC Tj Tstg Rating 100 100 5 5 40 150 -50~150 Unit V V V A W ℃ ℃ ELECTRICAL CHARACTERISTICS (TA=25℃) Characteristic Collector Cutoff Current Emitter Cutoff Current DC Current Gain Collector- Emitter Saturation Voltage Current Gain Bandwidth Product Symbol ICBO IEBO hFE1 VCE(sat) fT Test Condition VCB= 100V , IE=0 VEB= 5V , IC=0 VCE= 5V , IC=1A IC=4A , IB=0.4A VCE= 5V , IC=0.5A Min Typ Max 10 10 320 2.0 8 Unit µA µA 40 [ ... ]