IP rating is also known as Ingress Protection or International Protection ratings are defined to the international standard of EN 60529 (British BS EN 60529:1992). This standard is used to define the levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies such as tools, dirt and moisture. BIT-PT850 haevy duty pan tilt head features IP66 ingress protection. Below is explanation of IP66 rating: Protected from total dust ingress. Protected from high pressure water jets from any direction.