Astrozap Flexible Dew Shields for 10" Astro-Tech/GSO RC w/notches Fits 298mm dia. Optical tubes The dew shield is the basic component of the passive dew fighting system with the added feature of shielding the telescope from undesirable stray light. Felt-lined to help absorb moisture and to prevent extraneous light from reaching the optics and greatly improving contrast. Proudly manufactured in the USA!