Normally, low-pressure air can be used to clean off any dust and dirt between connectors and the top surface.
You can also use a clean cloth dampened with water and a mild detergent, or isopropyl alcohol to clean off any contaminates.
Normally use low-pressure air to blow away any dust or debris on the lenses (or use a soft lens brush).
To remove dirt or finger prints, clean with a soft cotton cloth rubbing in a circular motion. Use of a coarse cloth or excessive rubbing may scratch the lens surface and cause permanent damage.
For a more thorough cleaning, photographic lens tissue and photographic-type lens cleaning fluid or isopropyl alcohol may be used. Always apply the fluid to the cleaning cloth - never directly on the lens.
Caution should be used not to touch the SRM (Standard Reflectance Material) disk.
ONLY use clean, dry compressed air to remove any contaminates from the SRM disk in the calibration tool.
Store the calibration tool in the bag provided when not in use.