We were flying on Swiss Airlines from Chicago to Zurich. We are very dissatisfied with how Swiss Airlines employees handle their carry on baggage policy. It states on their website that the maximum size of a carry on bag is 55 cm (21.6 in). Our bag is exactly 21 inches including the wheels. When we were boarding, we were asked to check the size of the bag by fitting it into the measuring device. Our bag didn't fit it to our big surprise and to the surprise of the other passengers who had similar size bags. We measured airport device with a measuring tape and it was only 20.5 inches long. We have a picture of the measurement that we can submit. When we pointed out extremely politely to Swiss Airlines representatives that the Swiss Airlines device is incorrect, the representatives became very rude and cancelled our boarding passes. We were flying with our daughter who just had a surgery and was awaiting another surgery and had a lot of things necessary for a transatlantic flight. If we knew that Swiss Airlines only allows 20.5 inches, we would've packed differently.