Omg I was recently introduced to these and now I love them all. Got to collect them all. I have for the house, car , lake house , ban etc u name it. My fav is WiFi but it’s too expensive. So I use these economical ones cause I put them all over the house. The remote is a bonus. No need to get up. Same job as WiFi. 500 ml last a long time. I have tiny ones and is a headache to keep refilling and refill. So I start w these cause they last forever. Have not seen anything bigger than 500 ml ...yet. I think I am addicted to all these. They make house and places smells clean. They make my anxiety better. They make me relax. I also think the house gets cooler w these if they are on. Cooler as colder When the house inside is very hot. I also noticed since I have plants inside and outside the home that the ones inside have greener leaves. Plants loves these too. My stepson thinks I put this on so he could get better with a cough he had, and he did got better after I turned this one on. I never told him why I bought it.No idea how it helps w cought, but this is The best 2019 invention ever for me and my family. Got to catch them all!