The TMX005X-M features a clean, attractive design and ease of use. Large displays shows jumbo digital numbers, easy to read icons, and temperature readings in your choice of Celsius or Fahrenheit degrees. Measures indoor and outdoor temperature and humidity, using one included wireless sensor with 100 ft. range. Capable of reading 2 additional, optional sensors. Stores maximum and minimum temperature and humidity readings in memory, and displays comfort level. Scans automatically or manually, and can read outdoor temps ranging from -4F to 158F, using alkaline batteries, or from -38F to 158F, using lithium batteries. Unit can be used free-standing, or wall-mounted.