Absorbine UltraShield Sport protects horses from stable flies, horse flies, house flies, face flies, horn flies, deer flies, mosquitoes and gnats. It's sweat and weather-resistant formula stays active for up to 14 days and continues to work when the horse sweats and after rainfall. Features: Provides sweat resistance for heavy workouts in the hottest, most humid weather. Kills and repels flies and mosquitos, including those that may transmit West Nile Virus. Water-based formula gives horses' coat an oil-free shine without attracting dust. Citronella-scented spray stays active for up to 14 days.