Sometimes youth has a way of being brash while trying to educate customers so you can fulfil their needs or wants. Day after day of people not knowing what they want, the model, and sometimes even the make of equipment, you would like to make a point so they come with the correct information so you can give them the correct part and they are satisfied that you gave them the correct part. It beats having them return with the wrong part because YOU did not know what machine or serial number they own.