This part is a kind of semiconductor called SS8550.

Function of this product has PNP Epitaxial Silicon Transistor.

Manufacturers : Fairchild

Image and pinout :

Some of the text within the PDF file :

SS8550 PNP Epitaxial Silicon Transistor November 2014 SS8550 PNP Epitaxial Silicon Transistor Features • 2 W Output Amplifier of Portable Radios in Class B Push-pull Operation. • Complimentary to SS8050 • Collector Current: IC = 1.5 A 1 TO-92 1. Emitter 2. Base 3. Collector Ordering Information Part Number SS8550BBU SS8550CBU SS8550CTA SS8550DBU SS8550DTA Top Mark S8550 S8550 S8550 S8550 S8550 Package TO-92 3L TO-92 3L TO-92 3L TO-92 3L TO-92 3L Packing Method Bulk Bulk Ammo Bulk Ammo Absolute Maximum Ratings Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above t [ ... ]

SS8550 PDF Datasheet Download