its a humidifier...not a diffuser...putting oils in it can damage the membrane. The instructions are pretty strict with water only....
for the people asking they are $68 and are on amazon
https://www.amazon.com/Shine-Humidifier-King-Godzilla/dp/B075KDXZ1N
I was lucky enough to find this used at a record store so it was less expensive, it is on e-bay but always use caution buying used online!