Lacerta 20 cm Long Dew Heater Compatible with tubes of 60-70 mm circumference and 50 mm finderscopes, with a width of 3 cm. Requires 5V from a USB power source, preferably operated from a power bank.
Anyone who has observed in the cold of autumn and winter knows how problematic dew formation can be. A dew shield provides some protection, but here is the "real" solution. Dew heaters are small heating pads or heating wires that keep optics warm. They can be attached around the eyepiece or tube using Velcro straps. Especially recommended for Schmidt and Maksutov-Cassegrain telescopes, where the corrector lens is particularly prone to dew formation, but also useful for refractor telescope owners.
The dew heater should not be operated from a computer as it may cause damage!