IP(INTERNATIONAL PROTECTION)is defined by international standard IEC 60529, it classifies the degrees of protection provided against the ingress of solid objects ,and liquids in electrical enclosures.

IP degree is combination from two numerals:
First characteristic numeral - protection against the ingress of solid foreign objects
Second characteristic numeral - protection against the ingress of liquids
(More big of the numeral, the protection is more better)
| The first numeral(protection against the ingress of solid objects) | ||
| digit | Protection degree | |
| IP against solid objects | 0 | No protection |
| 1 | protected against solid foreign objects > 50mm | |
| 2 | protected against solid foreign objects >12 mm | |
| 3 | protected against solid foreign objects >2.5mm | |
| 4 | solid foreign objects >1.0mm | |
| 5 | dust protected | |
| 6 | dust tight | |
| The first numeral(protection against the ingress of liquids) | ||
| Digit | Protection degree | |
| IP against liquids | 0 | No protection |
| 1 | liquids vertical dripping | |
| 2 | liquids dripping (inclined 15 degrees) | |
| 3 | liquids spraying | |
| 4 | liquids splashing | |
| 5 | liquids jets | |
| 6 | Powerful liquids jets | |
| 7 | Temporary immersion | |
| 8 | Continuous immersion | |
For example: IP67
Digit 6 means: the project is dust tight
Digit 7 means: the project is protection against temporary immersion.