So economical, you'll want several for monitoring and recording environmental conditions. This hygrothermograph is so compact it fits almost anywhere. Record temperature and humidity on 7-day rotation. Range is 5 to 90% RH with 5% RH resolution. Temperature range is -6 to 40°C or 22 to 104°F with 2° resolution. Quartz-controlled drive is employed for accuracy; operates for six months on one AA battery. Includes two felt-tipped pens (blue and red), one 7-day rotation chart and one AA battery. Dimensions: 6"W x 7.4"H x 3.9"D. Shipping weight: 4 lbs.