Easy to use - just plug in. This lightweight fogger is the most economical way to kill mosquitoes and biting flies. Produces microscopic particles up to 7 times finer than mist. When applied before dusk or dawn, the fog floats and penetrates deep into landscaped areas where mosquitoes hide, killing on contact and creating a mosquito-free zone that lasts up to 6 hours. In about 5 minutes, the fog is gone so you can start enjoying the outdoors again. Takes an average of 10 minutes to treat a 5000-square foot yard. Use before backyard picnics, barbecues, outdoor parties and special events. This is the same effective system used by professionals to kill mosquitoes that may carry the Zika virus or West Nile virus. Features a 40-ounce reservoir and a trigger lock to prevent accidental dispensing of insecticide. For best results, use only with Black Flag branded Fogging Insecticides. For outdoor residential use only.