This is a great fuse holder. I bought it to replace the one that came with my Knukonceptz 4 gauge amp kit. The wiring in that kit is great, but the fuse holder leaves much to be desired. This seemed high quality and I wanted to give NVX a try. Well I'm very happy with it. Fits REAL 4 gauge with a little work, and everything fits right. My only gripe is that the fuse takes some effort to put into the stainless part of the holder. But other than that it's awesome, I highly recommend it.