Endure's gallon fly spray is a great solution to rid your horses's from insect bites. Formula is sweat resistant. Stays on and keeps working in wet conditions. This spray provides up to 14 days of fly control. Contains repelock, which is a special conditioner that binds to the hair shaft and will not sweat off. Protects against biting and nuisance flies, gnats, deer ticks, and lice. Provides the ultimate repellency, and quickly knocks down mosquitoes.