我搵到呢個。
"We get asked a lot about the "directionality" of high performance fuses. Our feeling is that the only way to reliably tell that a fuse is inserted into a given circuit with the proper orientation is to listen to them both ways. Taking a little time to listen to the fuse inserted one way, then again the other direction often results in a clear answer to the question "which way is best?"."
Quote from Synergistic Research SR20 Quantum Fuse Web page.