3M Ultrathon insect repellent was developed for the military to provide long lasting, time released protection against mosquitoes for up to 8 hours for the Aerosol product. Repels Ticks that may carry West Nile Virus and also mosquitoes, biting flies, chiggers, gnats, fleas and deer flies. Splash and Sweat Resistant. Unique 3M Polymer Technologh optimized to enhance the efficacy of DEET and provide time controlled release of DEET. Stable in Freeze/Thaw conditions. 5 year guarantee. Consistantly rated as a top insect repellent by independent testing labs. Tested in the harshest conditions of South America. Works longer with less DEET. Competitive products are alcohol based and when the alcohol evaporates you lose your protection. Ultrathon uses the time released technology to provide a longer lasting repellent. Sprays upside down.