I tested this device in an empty parking lot and measured parking spaces at an angle. I started at an end point, then walked along the park line, crossed the line opposite the parking lot directly in front to get enough clearance, then came back on the other side and finally went to the original stake out point. Imagine a parallelogram with no ends since it is a parking lot entrance. I noticed the screen shifting to accommodate the corners and when I finally got to the starting point there was a gap of about 1/8 inch. Do you know if the gap is important or if I made a mistake in the settings? I hope I can figure out how to reset the device or maybe try recalibrating it.