10Pcs F0.5AL250V 6X30MM 0.5A Fast Blow Fuse 0.5 Amp 250V F0.5AL Glass Fuse Fast-Acting Fuse. With overload and overcurrent protection. If the circuit fuse correctly placed, then the fuse will be in the current exception is raised to a certain height and heat when its fuse cut off the current, and thus play a role in the safe operation of the protection circuit.