Maxi Blade Fuses are the ideal option for the protection of higher amperage automotive circuits. This blade fuse has a rating of 40 Amps and 32 Volts. Blade Fuses are color-coded by amperage rating to ensure the correct fuse is installed. Fuses are a necessary component in an electrical circuit because they offer an essential protection by acting as the weakest point in a circuit. When a current is too strong, the fused element inside a fuse will heat up and break so that the current can no longer complete the circuit.