The JK250-800U with PTC Resettable Fuses Through Hole RoHS manufactured by Jinrui Electronic Materials is a resettable PTC fuse used in the protection of circuits and components against overloads. It is a thermal-type fuse that is designed to protect circuits from excessive current flow. It is designed with a temperature sensing device that trips when the temperature reaches a certain limit, breaking the circuit and preventing further damage. Additionally, the JK250-800U is manufactured using RoHS compliant components. It is designed with a through hole mounting design, making it a versatile and easy to install component. The fuse is also rated for 800V and has a 250A current rating.