The IP designation consists of the letters IP followed by two numerals. The first number indicates the degree of protection provided by the enclosure against solid foreign objects entering the enclosure or people being able to open it. The second number indicates the degree of protection provided by the enclosure with respect to the harmful entry of water. The higher the number, the more protected the device. For example, an IP66 rated enclosure is “dust tight and protected against powerful jets of water from any direction.”