SensorPush Wireless Thermometer/Hygrometer for iPhone/Android - Humidity & Temperature Smart Sensor with Alerts. Developed and Supported in The USA Flexible: Add a SensorPush G1 WiFi Gateway (sold separately) for data and alerts via the Internet Powerful range: For use all around the house. Up to 325' in ideal conditions (no obstructions) Designed with you in mind: Beautifully designed apps for Apple iOS and Android make monitoring easy Accurate: Swiss-made sensing component provides reliable, accurate measurements Set it and forget it: Pushes readings to devices via Bluetooth 4.0 and alerts you if there's a problem