Sawyer Premium Controlled Release Insect Repellent utilizes an advanced micro-encapsulated mechanism that significantly reduces the rate of DEET absorption by 67% per application, and extends the duration of its effectiveness. The repellent contains 20% DEET in an formula that controls the evaporation of DEET, allowing it to keep working all day. Odorless, non-greasy, and effective against ticks and ALL mosquitoes including those carrying West Nile Virus.