The TAJP156M006RNJ: This is a molded tantalum capacitor from the TAJ series, 15 µF with ±20% tolerance, rated at 6.3 V. The 0805 case (2.05 mm x 1.35 mm footprint) is a common size for compact consumer and industrial PCBs — hand-solderable with a fine tip, though the molded body means the part sits flat and reflow is cleaner. The 3.5 Ohm ESR is on the higher side for a tantalum of this value; it limits ripple current handling and makes this part better suited for bulk storage or decoupling on lower-frequency rails than for high-ripple switching supplies.
The 125°C ceiling is the absolute maximum — derate voltage above 85°C per standard tantalum practice to avoid field failures.