IP is an international standard used to define levels of sealing effectiveness of electrical enclosures against intrusion from things like tools, dirt, and moisture. The two numbers that follow “IP” each have individual meaning. 

The first indicates the degree of protection for people from moving parts inside the unit and also the level of protection of equipment inside the unit from things like tools, dirt, etc.The second digit defines the protection level that the enclosure of the product has from various forms of moisture (drips, spray, submersion).

This unit has a first digit of “2”, which means this product has protection from finger and from solid objects greater than 1/2” (12.5mm) in diameter.

The second digit of this product is a “1”, which means this product provides against vertically falling drops of water or condensation.