The 12D9.055SMT from Calex Manufacturing is a DC to DC Converter with Input Voltage 10.8 to 13.2 V, Output Voltage 1 9 V, Output Current 1 0.055 A, Output Power 1 W, Output Voltage 2 -9 V. Tags: Surface Mount, Buck/Step down. More details for 12D9.055SMT can be seen below.