Many table saws, router tables, band saws, etc. come with less than accurate miter gauges. The scale and pointer can be very inaccurate. This tool allows you to accurately set the miter gauge to some of the common angles. To use, just insert the miter gauge bar into the desired slot of this tool, loosen the miter gauge head and push it against the wall of this tool and retighten the miter gauge head. This tool can be used to set 0, 22.5, 30, and 45 degree angles. If you want to have the angle face in the opposite direction, just flip the miter gauge upside down before putting it into the desired slot. The slots were made for a Ridgid table saw miter gauge. The slot width is 0.75 inches. If you have a different slot width, you can adjust it by rescaling the x and y dimensions in your slicer.