The RB508FM-40SFH from ROHM Semiconductor is a Power Diode with Forward Current 0.12 A, Forward Voltage 0.40 to 0.66 V, Reverse Current 15 to 340 uA, Reverse Voltage 40 V, Repetitive Peak Reverse Voltage 40 V. Tags: Surface Mount. More details for RB508FM-40SFH can be seen below.