I thought they were pretty good at first. Used it to turn on the tail light on my auxiliary tach in my sleeper. I used them in conjunction with the fuse that controls my dash etc so I didn't have to cut and splice the tail light harness at my saddle gauge. Well I noticed my dash lights were flickering, I kept blinking through my headlight switches etc. Anyway I had a blown fuse in my radio so I went to check my fuse box and then saw horror. Those things melted my fuse box under the dash. After taking it out of the fuse box and cleaning everything, my dash lights and stuff worked fine again. Since then no problems. In short, they are shorted and giving me a big headache. My suggestion is to find another brand or bite the bullet and just plug into the wiring harness etc.