Jungle Formula Maximum Strength – Ozone friendly aerosol spray with 50% DEET for long-lasting maximum protection. The insect repellent factor is a quick and easy way to choose what repellent you need to protect yourself from mosquitoes, midges and other biting insects. The higher the factor, the better the protection. Insect repellent factor – 4 maximum Up to 10 hours maximum protection from a single application* For areas with a high risk of malaria and other insect transmitted diseases For adults and children from 3 years.