This part is a kind of semiconductor called 20N561K.

Function of this product has OXIDE.

Manufacturers : JOYIN

Image and pinout :

Some of the text within the PDF file :

JOYIN CO., LTD. Electrical Characteristics Type No. 20N561K Maximum Allowable Voltage ACrms DC (V) (V) 350 460 Varistor Voltage Maximum Withstanding Rated Energy V /1mA Clamping Surge Wattage 10/1000us Certification Voltage Current V@100A 1 Time 2 Times (V) Tolerance (V) (A) (A) (W) (J) 560 ±10% 920 6500 4000 1 312.0 The clamping voltage from 180M to 680L are tested at current 20A. Material of coating : Epoxy powder (Halogen free) Color of coating : Yellowish brown Storage condition Temperature: -40 ~125 / Humidity : 75%RH max. Status Operation temperature range(18V~150V) : -40 to 85 Operation temperature range(180V~1800V) : -40 to 125 Lead style : P : Straight type Y : Kink type I : Inside kink type E : Outside kink type DT H1 L1 DIMENSION : Type No. D max. 20N561K [ ... ]

20N561K PDF Datasheet Download