Holmes HM630-U Cool Mist Tower Humidifier with state of the art functionality combined with its great design that complements any home, this cool mist tower is ideal for medium rooms. It provides a refreshingly cool, invisible mist, as well as a digital humidistat which offers precise humidity control for your optimal comfort. FEATURES: Designed for medium rooms; Runs up to 36 hours per tank filling; AccuSet Digital humidistat; Contains an Antimicrobial Product Protection and Arm & Hammer treatment to key plastic parts; Filtercheck monitor; Dishwasher safe base; 16 hour timer. Uses 2 HWF100 filters (E Filters).