The clearly perfect angles will be the most practical notion you've ever used! Whenever a pattern tells you to draw a line.....DON'T!!
The clearly perfect angle tool "clings" to smooth sewing surfaces (no taping) so it's always in position ready to sew ANY 45 degree angle accurately. You will appreciate the Fabric Alignment Key and 1/4" & 5/8" seam guides. It's also color-coded for different techniques. And to answer one of the most common questions...No, it does not need to be removed to access your bobbin or move your table.
Here is a video highlighting a few of the techniques you can use with this tool.
Please refer to the photos for additional information and techniques.