This Lens Cleaning Cloth with Ultrasuede Gray Storage Pouch from Bluestar is safe to use on any optical glass, and cleans dust, dirt, and oils off the glass. Bluestar recommends hand washing the 10 x 10" gray cloth to prevent adding harmful particles from a washing machine to the cloth that might scratch glass surfaces. The cloth can be stored in the gray ultrasuede pouch which closes with a hook-and-loop closure.