Use this on a small 3" vise that had no pads at all. It seems fairly well made and gets the job done without shrinking to 4.5 inches. The downside is that the magnets aren't very strong, which is only an issue if you're trying to align a tool/item that needs to be blocked. The biggest problem is that the pads are so thick that I lose most of my jaw opening through the pads. If I could do it again I would buy thinner pads so I have more span. Since they are designed to be used with smaller vises (3-4.5) I think they will know the holes are smaller to start with. They end up working fine, but you lose the ability to use them on thicker items.