IP (Ingress Protection) Classes IP (Ingress Protection codes / classes based on EN 60529 (DIN 40050) define how well the “enclosure” of an equipment protects the unit against ingress of foreign bodies and liquids. The IP class is a 2 Digit number; the first digit stands for the protection against solids, the second digit describes the grade of protection against water. First digit (Protection against ingress of solids) : 0 = No protection 1 = Protected against objects greater than 50 mm diameter 2 = Protected against objects greater than 12 mm diameter 3 = Protected against objects greater than 2.5 mm diameter 4 = Protected against objects greater than 1.0 mm diameter 5 = Dust protected protection against dust deposits impairing function 6 = Dust tight Second digit (Protection against ingress of water) : 0 = Not protected 1 = Protected against dripping water (i.e. vertical plane) 2 = Protected against dripping water up to 15 degree angle 3 = Protected against spraying water tilted up to 60 degree angle 4 = Protected against splashing water 5 = Protected against water jet projected from a nozzle 6 = Protected against heavy seas or powerful water jets 7 = Protected against effects of immersion (temporary immersion) 8 = Protected against submersion (continuous immersion) The Neugart S-series units with its dedicated double lip shaft seal conforms with an IP 66. Even temporary immersion in water up to about 1 m depth will not interfere or limit the function of the unit, which would actually qualify for IP67. Unfortunately shaft seal manufacturer will not commit to any warranty therefore catalog value is listing the warranted value of IP65.