The IP51 and IP52 ratings indicate that the camera is protected against dust and dripping water. IP51 means the camera is protected against dust ingress to a level that would interfere with the operation and against vertically dripping water. IP52 offers the same dust protection but also protects against dripping water when tilted up to 15 degrees. These ratings make the cameras suitable for indoor use where dust and minor water exposure might occur. Axis Network Video documentation specifies the IP rating system and the levels of protection provided by different ratings.