New, more effective, gentler formula kills and repels flies, mosquitoes, gnats, and ticks on horses for up to two weeks. The most complete protection available for horses. Water and perspiration resistant. Protects horses both day and night (when gnats and mosquitoes feed most often). Easy-to-use, no-spill applicator with resealable cap. Can be used with any Permethrin-based fly spray for horses.Size: Each box provides up to six (6) weeks of protection.