I installed this for my viofo a119 and haven't had issues so far. It doesn't come with any instructions and I've never used a fuse tapper before so I wasn't exactly sure how that worked. So I went down to my local auto zone and found the exact same product and took a picture of the back of the packaging so I had instructions.
You plug the fuse tapper into an existing slot on your fuse terminal board, I used my radio fuse slot. You take the fuse that you removed and put it into the fuse tapper, then put the fuse you're going to use for the dash cam and put that into the tapper as well. The kit doesn't come with fuse you need for the dash camera, but I just used a 5 amp automotive blade type fuse.