Ingress Protection (IP) ratings are developed by the European Committee for Electro Technical Standardization (CENELEC) (NEMA IEC 60529 Degrees of Protection Provided by Enclosures - IP Code), specifying the environmental protection the enclosure provides.

The IP rating normally has two (or three) numbers:

1. Protection from solid objects or materials

2. Protection from liquids (water)

3. Protection against mechanical impacts (commonly omitted, the third number is not a part of IEC 60529)

Example - IP RatingWith the IP rating IP 65, 6 describes the level of protection from solid objects and 5 describes the level of protection from liquids.