Standard Features - All-In-One Control Controls temperature and Indoor Air Quality (IAQ) products such as humidification, dehumidification, ventilation, and air filtration monitoring - all from a single control in the living space - 7-Day Programming Allows separate programming for each day - Touchscreen Interaction Easy-to-follow menu-driven operation simplifies programming by responding to your choices - Smart Change/Check Reminders Let you know when to service or replace filters, UV bulbs (based on actual usage) and humidifier pads - Whole-House Telephone Access Works with your existing telephone line to offer control of your home's temperature and Indoor Air Quality over the phone - Model Numbers YTH9421C1010, YTH9421C1002, TH9421C1004 - 5-Year Warranty