Best design we've found, for ease of use and cleaning up. Simple pull-out operation: fill small tray with water, add drops of oil; replace the wheel which turns and allows a quiet fan to blow air across it, releasing the fragrance into the air. This diffuser will scent a quite large amount of space as long as there is adequate air circulation.

Users really like this one.

Black. Dimensions: 5"W x 7.5" L x 6" H.