This part is a kind of semiconductor called SCK-2R55A.
Function of this product has Power Thermistor.
Manufacturers : TKS
Image and pinout :
Some of the text within the PDF file :
SCK-SERIES Part Number Code SCK-SERIES Part Number Code [A] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 SCK Product Code NTC-Surge Current Killer DISC 05 08 10 13 15 20 Ø Size 5Ø 8Ø 10Ø 13Ø 15Ø 20Ø Part No. (R25) 101 10Ω /1A 053 5Ω /3A 2R55A 2.5Ω / 5A 203 20Ω / 3A 1R38 1.3Ω /8A 106 10Ω /6A : : The Tolerance of R25 L ±15% M ±20% S I IC IQ A E : Lead Wire Style Straight Lead Inner Kink Lead Inner Kink Cutted Lead Inner Kink Wider Pitch Cutted Lead Tapping Hole Pitch: 12.7mm; Box Tapping Hole Pitch: 15.0mm; Box : [B] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Product Code SCK NTC-Surge Current Killer DISC 05 08 10 13 15 20 Ø Size 5Ø 8Ø 10Ø 13Ø 20Ø 20Ø Part No. (R25) 101 10Ω /1A 053 5Ω /3A 2R55A 2.5Ω /5A 203 20Ω / 3A 1R38 1.3Ω /8A 106 10Ω /6A : : T [ ... ]