The NTE251 (NPN) and NTE252 (PNP) are silicon complementary Darlington transistors in a TO3 type case designed for general–purpose amplifier and low–frequency switching applications.
Full spec sheet:
https://www.nteinc.com/specs/200to299/pdf/nte251.pdf
NTE252 PNP 100V 20A Darlington Power Amp TO-3
SKU: NTE252
$9.34Price