Justin,
I'm curious how his works. When you mount it on a tripod does it have another laser that shoots straight down to show you where on the ground the end point is? Or does the tripod have a 4th arm that goes straight down that you can use to see this?
I looked in Wikipedia and it says this:
Positioning the tripod and instrument precisely over an indicated mark on the ground or benchmark requires techniques that are beyond the scope of this article.