This Waterless Electric Diffuser uses the latest technology - "Super High Frequency Atomization" that has a diffuser range of 100-1000m3, and managed to bringing atomized particle size from (10-20um for conventional ultrasonic diffuser) to 0.7-1.2um. Meaning the diffuser is much quiter, more pure and last much longer (as the atomizer sheet has no holes and will not be blocked) Dimension : 72mm D x 125mm H