The 1SMB5955BT3G from onsemi is a Power Diode with Forward Current 0.0021 A, Forward Voltage 171 to 189 V, Reverse Current 1 uA, Reverse Voltage 136.8 V, Repetitive Peak Reverse Voltage 136.8 V. Tags: Surface Mount. More details for 1SMB5955BT3G can be seen below.