This part is a kind of semiconductor called SF14.

Function of this product has 1.0A SUPER-FAST RECOVERY RECTIFIER.

Manufacturers : Diodes Incorporated

Image and pinout :

Some of the text within the PDF file :

SF11 - SF14 1.0A SUPER-FAST RECOVERY RECTIFIER Features · · · · · Low Leakage Low Forward Voltage Drop High Current Capability Super-fast Switching Speed < 35ns Plastic Material: UL Flammability Classification Rating 94V-0 A B A D C Mechanical Data · · · · · DO-41 Case: Molded Plastic Terminals: Plated Axial Leads, Solderable per MIL-STD-202 Method 208 Polarity: Color Band Denotes Cathode Approx. Weight: 0.3 grams Mounting Position: Any Dim A B C D Min 25.4 4.1 0.71 2.0 Max 5.2 0.86 2.7 All Dimensions in mm Maximum Ratings and Electrical Characteristics Ratings at 25°C ambient temperature unless otherwise specified. Single phase, half wave, 60Hz, resistive or inductive load. Characteristic Maximum Recurrent Peak Reverse Voltage Maximum RMS Voltage Maximum DC Block [ ... ]

SF14 PDF Datasheet Download