My Bandmaster Reverb blew a fuse when the rectifier lamp died. I replaced the lightbulb and everything else was fine (tip: build a $10 current limiter with a lightbulb and electrical equipment if you're looking for a short!). I bought some unnamed Chinese fuses off eBay but I just didn't trust them so I ordered these. I now have complete confidence that my prized vintage amp is well protected. As others have pointed out, they no longer come in a handy little roll-top case, but you can easily find vintage fuse housings online.