The corrector plates on Maksutov and Schmidt-Cassegrain optics are located in an exposed position at the front end of the tube. Even low levels of humidity lead to fogging of the optics with dew.
Refractors are usually already supplied with a dew shield and in Newtonian telescopes the entire tube acts as a dew shield. For SC and Maksutov telescopes, on the other hand, a dew shield is a very useful accessory.
This dew shield from Astrozap is made of flexible plastic, so that it can also be transported flat. They are quickly and easily attached to the telescope using a Velcro fastener. Inside, they are lined with felt to block stray light. Due to their low weight, they do not put any strain on the mount.