Indoor and Outdoor temperature and humidity. Minimum and Maximum temperature and humidity memory. Programmable temperature alert on all three channels. Includes 1 RS211 transmitter, optional transmitters sold separately. Transmission distance 426 ft (feet) 130 m (meters). Blue LED (light emitting diode) backlight. 1 year warranty. No. MRI-822MX: Scale: Fahrenheit & Celsius, Readout: Digital, Temperature Range: -40 F to 158 F -40 C to 70 C, Battery Type: 4 AAA Batteries (not included), Pkg Qty: 1, Package Type: Clamshell Thanks for shopping Hipp Hardware Plus's Online Store for all your DIY and Home Improvement needs. Remember Hipps Help!