The SPF1K12S3R3 from Calex Manufacturing is a DC to DC Converter with Input Voltage 10.8 to 13.2 V, Output Voltage 1 3.3 V, Output Current 1 260 mA, Output Power 1 W, Isolation Voltage 3 kV. Tags: Through Hole, Buck/Step down. More details for SPF1K12S3R3 can be seen below.