ProAligner - Storage & Transport - A to B

This tool is simple in concept but not simple in execution. The procedure is to add and subtract numbers on the rulers by line of sight and therefore make the measurements equal. But the execution is problematic. First, the directions are poor, and the YouTube video doesn't help much. Second, in order to use it, you set it up under the tires, you had better have eagle eyes. When one is in the front, youare so far from the rear ruler, it is hard to see. The light must be a bright sunny day and a cloudy day puts the small markings in the shadow of the bike. Second, if one has anything under the bike, like a bash plate for example, one has to position it lower and farther away to see. One needs binoculars to see the numbers. I am sorry I bought it.