The first digit defines the protection against solid objects.
0 No protection.
1 Protection against solid objects larger than 50mm.
2 Protection against solid objects larger than 12mm.
3 Protection against solid objects larger than 2.5mm
4 Protection against solid objects larger than 1.0mm
5 Protection against dust. (The entry of dust is not prevented, but without entering in large quantity).
6 Leak-proof dust.
IP protection
IP (1st digit) (2nd digit).
The second digit defines the protection against liquids.
0 No protection.
1 Protection from dripping water.
2 Protection against dripping water at an angle of 15 °.
3 Protection against spray water at an angle of 60 °.
4 Protection against water splashing.
5 Protection against water sprayed from a hose from any direction.
6 Protection against water sprayed with force.
7 Protection by immersion in water. (Under pressure and time conditions).
8 Protection from immersion in water. (Under conditions specified by the manufacturer).