The 250v is just the maximum the fuse can take after it has blown. In operation, the voltage across the fuse is always very, very close to zero volts because until it blows, the fuse acts like a short.Interesting.......... one guy on the other thread said his fuse was also 250ma / 250v. That's one I can't figure out because a Seadoo is a 12v system just like a car not 250v