Celestron Aluminum Dew Shield with Cover Cap - 14"The Celestron Aluminum Dew Shield with Cover Cap is an essential accessory that protects your telescope tube in the field. The dew shield reduces radiative cooling of the Schmidt corrector lens to the night sky, thus keeping the lens below the dew point longer preventing dew formation on the lens. Additionally, the Aluminum Dew Shield increases image contrast by blocking stray light from entering the telescope for better viewing and astroimaging. Use