Best Use: Eliminates mosquitos and other biting insects on your patio or deck so you can enjoy the evening. Benefits: Kills biting insects on contact! 8 hours of residual protection against mosquitos. Kills mosquitos that may carry West Nile Virus. Each can treats an average patio four times (20" by 25" size). Will repel mosquitos from treated surfaces such as on and around outdoor lighting. Use Tips: Spray at least 10 minutes prior to using the patio area. Treat areas where mosquitos are likely to hide including and especially the undersides of trees and shrubs near ground level. Treat the underside of tables and chairs where mosquitos may land.