Maintaining proper indoor humidity and temperature has important benefits to your health, comfort, home, and possessions. Low humidity can lead to dry air symptoms like skin irritation, itchy eyes, nasal problems, and illness. It can also damage hardwood floors, moldings, and valuables like musical instruments. High humidity can promote the growth of mold, bacteria, viruses, fungi, dust mites, and other asthma inducing agents. The AcuRite digital temperature & humidity monitor empowers you to check comfort conditions at a glance, and take action when your indoor environment needs adjustment. Powered by 1 AA alkaline battery (not included). it's more than accurate, it's AcuRite.