.The JK250-1200U with PTC Resettable Fuses ThroughHole RoHS is a surface mountable resettable fuse manufactured by Jinrui Electronic Materials. It is primarily used in high current applications, such as computers, telecommunications, and industrial controls. This fuse is composed of a special alloy, which changes resistance when heated in order to decrease the current. Once the current has dropped to a certain level, the fuse automatically resets itself. The JK250-1200U has an operating current of 250 amps and a voltage rating of 1200 volts. This fuse has a current rating of 0.25 Amps under normal operational temperature range of -40 to +125°C. It is RoHS compliant and meets safety, quality, and protection requirements of devices and systems which need continuous protection from electrical failures and overloads.