I conduct workshops and travel with one personally (in my laptop case) and use it for telephoto lenses mainly. Wide angles tend to be harder to calibrate. It is made of laser cut plastic and there was a lot of time and effort put onto it's accuracy and ease of use - especially the alignment system and the fact that you can mount it on a tripod or light stand is a great asset as well. I use it to help people align their lenses at workshops all the time and while you can make a home made version this is much more accurate and long lasting - some friends for instance can share one since it's not something you need to use every day.