General Tools FD08 Digital Formaldehyde Meter Ideal for measuring levels of gaseous formaldehyde (HCHO) as part of a workplace indoor air quality (IAQ) maintenance program Meets U.S. National Institute for Occupational Safety and Health's (NIOSH's) acceptance criterion; CE and RoHS approved Tracks, calculates and displays three cumulative formaldehyde gas metrics; measures relative humidity (RH) and temperature in Fahrenheit or Celsius Large backlit dual-readout LCD; one-button calibration to 0 ppm in fresh air; user-adjustable high concentration audible alarm threshold; tripod mount Includes instrument, soft pouch, user's manual and warranty; power source is 4 AAA batteries (not included)