Tested, very clean, includes its original HMT337 probe with a sintered filter and user's guide (209 pages pdf). Unit is a Vaisala HMT337 Dewpoint & Temperature/Humidity transmitter with digital display. A Power-1 supply (120VAC to 24VDC) can easily be added inside (not included). High quality unit, made in Finland. Industrial surplus from a closing plant in Montreal (Quebec, Canada). Minor surface scratches only, none on the screen. The HMT337 probe included is for demanding processes, with an optionally warmed and vapor tight probe head.