Please do not consider this device. I read in a previous review that it was "a bit tight" for a mini fuse and that can't even begin to describe it. First, I couldn't even insert the included fuses into the unit with finger pressure without damaging the fuse. Inserting the fuse requires such force that any lateral pressure will instantly twist the fuse, rendering it unusable. In desperation, just to make sure the fuse slot was just poorly designed and needed to be opened up a bit, I took a couple of channellocks to line the fuse up so it wouldn't twist the fuse. I inserted the fuse, but after removing the fuse (which also required pliers) the slot was still too narrow to insert a new fuse without reusing the channellocks. The only reason I wanted to use this particular device was because it's advertised as 20 amps, but I'll never know if that will work. I bought 2 of these because I needed this and this unit is so poorly constructed that I couldn't take the second and fit in the first or vice versa. I had to go to the local AutoZone and select a lower rated Bussmann 10 amp fuse tap and I recommend you do so if you are considering buying one of these. In the end I absolutely do not recommend this product, it is poorly designed and just doesn't work.