Co.,LtdThis electronic part is a PTC Resettable Fuse designed for 1206 sized SMD (Surface Mount Devices). It is rated for 30V and is manufactured by Jinrui Electronic Materials Co., Ltd., a company based in Shenzhen, China. It is compliant with RoHS (Restrictions on Hazardous Substances) standards and has a marking of JK-NSMD050-30V. PTC fuses are an alternative to standard fuses as they automatically open and then reset themselves after the overload has been removed. This makes them useful for protecting delicate circuits from power spikes and surges.