Venstar T3950-IAQ is a smart digital thermostat with a built-In indoor air quality sensor and compatibility with VenNet wireless sensors. It is a switchable (non-programmable or 7-day programmable) thermostat that controls up to 4-Heat/2-Cool (4H/2C) stages. It controls humidification, dehumidification & reheat with adjustable timers and dead bands between stages.