This Hygrometer Sensor measures ambient temperature and humidity and automatically triggers the antifogging demister in the Vaonis Vespera Exploration Station digital telescope. Fog on your lens will affect the quality of observations and photos taken with the Vespera, but the Hygrometer Sensor knows when to chase it away with the demister's lens-warming capability. The sensor fits discreetly into the Vespera's optical arm and is compatible with the use of filters.