The Portable gas detector Riken Keiki with type Multi gas, have measurement type gas TOXIC (CO) and Oxygen (O2) with detection range 0-300 ppm / 300-2000 ppm (CO) and 0-40vol% (O2). Newly developed R sensor installed for improved performance. Three-year sensor warranty, power source with AAA Alkaline or Ni-MH batteries 2 pcs.