As a Smart thermostat, ComfortLink II XL850 delivers an intuitive, colorful, user interface that you can easily control from phone, tablet, or laptop so that you can achieve ideal home comfort or energy savings from virtually anywhere. The XL850’s accompanying Z-wave^® devices enables you to access over 200 devices in your home for easy monitoring, so homeowners can keep tabs on their home 24-7 and get real-time data and diagnostics help if there’s ever a problem. No matter the season, you can tap into the comfort you deserve with Trane’s popular ComfortLink^® II XL850 thermostat.