Mine is a medium sized room surrounded with trees, so there is a problem with mosquitoes. I bought all out and it worked for the first few days, but really dissapointed me after that! It claims to last upto 45 nights but that is of no advantage to us because after a few nights it does not work at all! Even if the scent comes out from the machine later on but it isn’t effective in the room at all! So, it is a waste of money. I won’t recommend using it.