Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good when it works, but not much of the time

When it is working it certainly does a fair job of getting rid of mosquitoes. It has only worked about 1/4 of the summer. The replacement items (the net and the scent) are expensive for what you get. Do not buy these from the manufacturer. I had to blow out the system 4 times before it finally started working again this summer. Blew $10 for these CO2 cartridges that should be about a $1 each. They are similar to beverage cartridges, except they have a thread on the end (so you can't use any other cartridge.) When it finally dies again, it is going to the trash.