I also looked and verified measurements. Thank You!It's under the advanced tab on one of the drop downs. And I think you may need to log in as a tech not owner to get access to it. It basically is a measurement in mm of where the sonic is looking to see input. And I think it's a 300mm buffer. So if the floor is literally 2200 mm from the sonic you'd set the upper setting to 1900 and the lower to 2500. To make them more accurate.