AMPELE 20PCS High Quality Fastblow Glass Fuse Current: 3A Voltage: 250V Dimension: 6x30mm(0.24 x 1.18 inch) * Size may vary slightly but still be compatible. The role of the fuse: work as a sacrificial device to provide circuit protection. When a circuit is abnormal, the current constantly rises, and the increased current may cause damage to some important components in the circuit, or it may burn the circuit. The fuse will cut off the current and protect the circuit when the current abnormally rises to a certain level.