The 12D12.042SMT from Calex Manufacturing is a DC to DC Converter with Input Voltage 10.8 to 13.2 V, Output Voltage 1 12 V, Output Current 1 0.042 A, Output Power 1 W, Output Voltage 2 -12 V. Tags: Surface Mount, Buck-Boost. More details for 12D12.042SMT can be seen below.