The scent diffuser uses no heat or water to function, keeping the essential oil in its natural state as it becomes a mist. The scent diffuser is made of natural pine wood and hand-blown glass external components having no plastic parts to corrode when in contact with the oils like most other diffusers, meaning with proper care, your diffuser can last for many, many years. This unit has a built-in timer function that runs turning on and off every five minutes then shutting down after 3 hours. It is perfect for spas, message studios, yoga studios or normal users who want their 10M x 10M space filled with essential oil aroma. These units also make amazing and memorable gifts as they are stunningly beautiful, hand blown pieces of functional art. The noise range of the scent diffuser, which uses an internal air pump, ranges from 20dB to 38dB depending on the power level setting.