Maybe trying to make that for a different battery! I thought Duracell Powercheck was a failure... don't see it on batteries these days because people got wise that it merely depletes the battery that bit more.
The datasheet for the resistor says wire wound. Most likely nichrome. The 300 W rating is with a heatsink and is 150 W in free air. That would lead to 3.9 amps (R*I^2) for 150W. With a 2.75" x 8" body, that can be a number of turns.
Generally, the TJT300 series typically uses wire-wound resistors internally. For specific information, I recommend directly checking the PDF to understand the basic technical specifications and some physical characteristics. I haven't found any related explanation videos on YouTube.
