The Lifesystems Expedition 100+ Plus is a dual-action formula which combines natural pyrethroids with a high concentration of DEET to provide maximum, long lasting protection. Natural pyrethroids act as a contact repellent so any insect actually landing on the skin will be deterred from biting. Each application of Lifesystems Expedition 100+ Plus will last up to 10 hours - high humidity can lead to excess sweating and a slightly reduced time on the skin). Not suitable for children.