12 HOUR Ultrathon is the longest lasting and most effective insect repellent on the market today. It repels mosquitoes for over 12 hours and ticks for over 9 hours, and is alos effect against biting flies, gnats, chiggers, and fleas. Ultrathon contains 33% DEET in a controlled-release polymer. Moister resistant--Lasts through splashes, perspiration and rain. Used by the U. S. military because of its effectiveness. Also repels terrestrial leachers in tropical areas where pests occur.