What this Schottky pair is for
The STPS20L120CFP is a dual Schottky rectifier from STMicroelectronics, configured as a common-cathode pair in a TO-220FPAB through-hole package.
STMicroelectronics lists the STPS20L120CFP as Obsolete.
Key ratings for the bench and the board
The 120 V reverse voltage gives comfortable derating margin on a 48 V or 60 V bus — you are not riding the absolute maximum. The 860 mV forward drop at 10 A is typical for a 120 V Schottky at this current density; expect about 8.6 W conduction loss per diode at full load, so the full-pack case needs a decent heatsink or forced air. Reverse leakage is 120 µA at 120 V — negligible at room temperature but it doubles roughly every 10 °C junction rise, so budget for it above 100 °C. The junction temperature limit is 150 °C max, which is standard for power Schottkys.