I have placed the SR20's into my RELs. They are the same amperage rating as the stock fuses. I am doing some listening comparisons of music well-known to me, and so far, there may be a bit more depth--not sure yet--hard to quantify at this point. I have not changed my sub volumes or crossover points. There may be some burn-in potential--or not--in these rather small fuses. Perhaps it would helo to push the amperage ratings for a larger filament. I have doubled the ratings in my Maggies to 5 amps for tweeter, 10 for midrange and have never had a problem--not worried at all. The SR's certainly do not detract in any way, and it's a fun tweak. My thanks to all.