This is a 25D681K varistor, a passive electronic component used to protect circuits from excessive voltage. It is Radial Leaded, with a 10mm pitch (P=10mm), and manufactured by SURGE-GARD according to ROHS standards. It has a rated voltage (VR) of 1.12kV, energy dissipation (J) of 450J, capacitance (C) of 950pF at 1kHz, a voltage clamping (VC) rating of 560V, a maximum voltage (VM) of 420V, and a lower and upper voltage range (VBR) of 612V-748V. The maximum current rating (IR) of the part is 15kA.