The unit is a DC photoelectric smoke alarm. The device operates with a 9V battery (6LR61 or 6F22), with a battery life of at least 1 year. Using photoelectric technology, it is more sensitive to detecting slow-burning fires that smolder with dense black smoke, with little heat, and that can smolder for hours before developing into a fire.
The device does not contain radioactive material that is harmful to the environment.