The DF2S20FS from Toshiba is a Power Diode with Dynamic Resistance 50 ohm, Reverse Current 0.5 uA, Reverse Voltage 18.8 to 21.2 V, Repetitive Peak Reverse Voltage 15 V, Peak Reverse Voltage 15 V. Tags: Surface Mount. More details for DF2S20FS can be seen below.