We have been calibrating the sprayers this spring and greatly appreciate the Spoton calibration tool. Instead of having to collect the spray for one minute in a bucket of water and measure the output, we can quickly find out how many gallons per minute output using this tool. To check this out see https://innoquestinc.com/product/spoton-sprayer-calibrator-model-sc-1/ . It has certainly made this spring chore a lot easier!!