This part is a kind of semiconductor called KSD-100.
Function of this product has Thermal Protectors.
Manufacturers : WHOLESOME
Image and pinout :
Some of the text within the PDF file :
KSD Series Thermal Protectors Dimensions (units in mm) Materials Casing: Plastic and/or Metal Operating Temperature 60℃ to 150℃ Tolerance ±5℃ Reset Temperature 15℃ to 50℃ Reset temperature less than operating temp. (customizable) Resistance Less than 50 mΩ Hi-Pot test 1500vac 0.5mA 1min Endurance 10,000 cycles Rating AC250V 5A; AC115V 8A; DC24V10A Construction (units in mm) RoHS Temperature Characteristics Model No. Operation temperature (Ԩ) KSD-60℃ KSD-65℃ KSD-70℃ KSD-75℃ KSD-80℃ KSD-85℃ KSD-90℃ KSD-95℃ KSD-100℃ KSD-105℃ KSD-110℃ KSD-115℃ KSD-120℃ KSD-125℃ KSD-130℃ KSD-135℃ KSD-140℃ KSD-145℃ KSD-150℃ 60±5 65±5 70±5 75±5 80±5 85±5 90±5 95±5 100±5 105±5 110±5 115±5 120±5 125±5 130±5 135±5 140±5 145±5 150±5 Rest [ ... ]