Bests & Worsts Reviews from Amazon

I used it to dial in my table saw, but after making cuts, they were out of alignment. I used the old fashion way by measurements and everything was off. I realigned according to the old fashion way and my cuts were perfect. This tool is worthless being a full 3 degrees off. I contacted the seller and they said they'd talk to their managers about replacing it. They never came back. I would not have written this if they have been responsive. I've uploaded a video of setting it to zero, rotating it clockwise and counterclockwise showing its inaccuracy.