General Tools DTR900 Inside/Outside Digital Thermometer with Minimum/Maximum Memory Inside/Outside Thermometer with Minimum and Maximum Memory Industrial thermometer simultaneously displays indoor and external probe temperature as well as time Thermometer stores and recalls minimum and maximum indoor and remote temperatures with time and date stamps; look back and monitor change over time The digital thermometer sensor is fast responding; one switch toggles Fahrenheit or Celsius display and the date and time format The temperature display mounts on a wall or other flat surface; the exterior probe is thin enough to fit under a window and is waterproof Perfect walk-in refrigerator thermometer, for monitoring reach-in boxes, greenhouses and other household and lab applications