Vortex Optics Fog Free Lens Cleaning Field Field Kit This lightweight kit will soon top your "Don't leave home without it" list. Everything you need to keep your optics sparkling clean in the field. Use the soft bristles of the Ultra brush to safely remove particles off lens, bristles retract for easy storage. Apply the lens cleaner for effective cleaning and anti-fog protection without affecting optical properties. Clean off fingerprints and other smudges off your riflescopes, sights, binoculars, monoculars and spotting scopes with the Vor Tek microfiber cloth.