This is a surface mount fuse 0603 RoHS-compliant, with a voltage rating of 4500V, manufactured by AEM. It is constructed from two small metal strips bridged by a piece of organic resin and is designed to act as a safety device that will open an electrical circuit when a high current is detected, protecting components from overheating or damage. Its 0603 size allows it to fit into tight spaces, making it an ideal solution for those working with small electronic components.