Key Delta Aqua has both knockdown, residual and repellent activity against most insect species. Repellant activity may prevent insects coming into contact with residual deposits of Key Delta Aqua. It is a high quality suspension concentrate formulation with a very small particle size for optimum contact with insects. 90% of the active ingredient particles are smaller than 10 microns in diameter. Key Delta Aqua is suitable for treating all surfaces and gives improved residual activity compared to EC insecticide formulations on porous surfaces such as unpainted brick, concrete block, timber or fibrous cement.