I wear this underwear when traveling abroad. Only need 3 pair regardless of how long the trip - 3 days or 3 weeks. They are breathable and lightweight. You can wash them in the hotel sink with some bar soap or shampoo and hang them to dry overnight. They are dry the next morning. So, 1 pair to wear, 1 pair to wash, and 1 pair for spare. While the price may seem expensive, they are worth the $$$. Buy them.