Protect your home from moisture and mildew without a second thought by installing a DewStop humidity and condensation fan switch. Many people will turn their bathroom exhaust fan on before a shower and tend to leave it on much longer than needed. This practice can generate unnecessary energy usage. DewStop is easily installed - simply connect your new or existing bathroom exhaust fan to the DewStop switch, and its Condensation Sentry turns the fan on only when it senses condensation and will run until the room is dry, saving electricity. In addition, the switch includes a manual on/off switch and a 30 minute timer.