SWAT is a ready-to-use insecticide for horses containing the pyrethroid insecticide 'Permethrin' in a non-irritant formulation with a high residual efficacy against Buffalo Fly, Stable Fly and Sand-flies. Rain resistant and low irritant. Highly concentrated. 250mL will provide 2 months protection for 1 horse (8 applications). 500mL will provide 4 months protection for 1 horse (16 applications).