22 µF, 20 V, 200 mΩ ESR — the three numbers that clear the BOM line
The 200 mΩ ESR keeps ripple heating low in a DC-DC output filter — a 1 A ripple current dissipates only 200 mW, well within the case's thermal budget at 125 °C. The ±20 % tolerance is standard for tantalum electrolytics — the capacitance at 20 V bias will measure near the nominal value, but the derating rule (50 % of rated voltage for solid tantalums) still applies: in a 12 V rail, this part runs at 60 % of its 20 V rating, which is conservative enough for most designs.
-55 to 125 °C — military-temperature deployment
The molded case construction resists moisture and mechanical shock better than dipped tantalums in these environments.