This part is a kind of semiconductor called GS1000FL.

Function of this product has SURFACE MOUNT RECTIFIER.

Manufacturers : UPM

Image and pinout :

Some of the text within the PDF file :

UPM GS1000FL~GS1010FL SURFACE MOUNT RECTIFIER Voltage Range 50 to 800 Volts Current 1.0 Amperes Features * For surface mounted applications * Low profile package * Ideal for automated placement * High temperature soldering : 260°C /10 seconds at terminals * Glass Passivated Chip Junction * Pb free product are available : 99% Sn above can meet Rohs environment substance directive request DO-41 SOD-123FL 0.117(2.95) 0.104(2.65) 0.077(1.95) 0.064(1.65) 0.042(1.05) 0.029(0.75) 0.043(1.08) 0.034(0.88) 0.008(0.20) 0.004(0.10) Mechanical Data Case: SOD-123FL, Plastic Terminals: Solderable per MIL-STD-202G, Method 208 Approx. Weight: 0.0168 gram 0.145(3.70) 0.139(3.55) 0.029(0.75) 0.017(0.45) Dimensions in millimeters Maximum Ratings and Electrical Characteristics PARAMETER Marking [ ... ]

GS1000FL PDF Datasheet Download