My wife is a quilter and uses these to cut different sized radius corne. She had bigger and smaller store bought veio but needed a new size for a pattern she was creating. The guide is lined up such that the flat edges are in the corner of the fabric then you cut along the radius with a cutting wheel and get a perfect edge every time. This has a 2.5" radius (5" diameter) and a hole for mounting to a peg board. You could scale it for any size but the mounting hole might get wonky. The mounting hole is chamfered on both sides. To customize he I embossed her company name into the top.