New but open box. Requires 3 AAA batteries (listing does not include batteries). Description copied from retailers website: Simple, always-on radon detector with short and long-term radon levels displayed on integrated LCD display. A best-seller, with radon-sensing technology trusted by professionals. https://www.airthings.com/home?utm_campaign_id=17735322232&utm_device=m&utm_adgroup=&utm_matchtype=&utm_network=x&utm_placement=&utm_target=&utm_source=google&utm_medium=cpc&utm_campaign={campaign}&utm_term=&utm_content=&hsa_acc=8596017755&hsa_cam=17735322232&hsa_grp=&hsa_ad=&hsa_src=x&hsa_tgt=&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gad_source=1&gclid=Cj0KCQiAv628BhC2ARIsAIJIiK-ZXcNaQ6HswhUmEmMyB16N3HAGlC6IKp3O7YVgMzYknEVnLFTbtUYaAjXVEALw_wcB