Hunter 31528 Microban Cool Mist/Warm Mist Humidifier, 2-Pack 2-pack contains one 31208 cool mist small room and one 35209 warm mist medium room humidifier featuring microban antimicrobial protection Warm mist model has medicine tray and a bonus bottle of vaposteam Cool mist model has uvc technology and scent tray with bonus scent pad Both humidifiers have a 24 hour run time Both humidifiers feature filter-free operation