I just played around with this tool a little to get a gist of it's limits. It's well made, the 4 rulers can be used screwed together, and comes completely apart to store in a small space. It works for literal contstruction measuring and, in conjunction with a triangle makes angles easy. For architectual drawing, the unit has limitations with respect to size. But, if used with other measuring tools, you can really have a lot of fun. Reminds me of Spirograph when I was a kid. Good gift for the avid angle loving architect/draftsman, artist!