IP66 refers to scales that are good for heavier washdown applications. IP means ingress protection and the numbers carry meaning as well. The first 6 means there will be no intrusion of dust into the enclosure. The second 6 means that the scale can be pressure washed, with room temperature water, through a high powered 12.5 mm nozzle from any angle. For more information check out our blog on IP Ratings Explained.