Material: 96% nylon + 4% spandex Ergonomic design: The waist pack is designed to hold objects securely and not wobble, even after strenuous movement. With the attachment design, you can easily adjust the position of the items you hold without having to remove them from the belt pouch. Comfortable materials: Our running fanny packs are made up of high-quality athletic technical fabrics that prevent chaffing, bouncing and distraction. The moisture-wicking fabric also absorbs sweat to keep your body cool and dry. Slim Waist Pack: Made of super stretchy material, the waistband conforms to your body. It's designed to be slim so you can run without feeling your belongings. Even when carrying your items, you won't feel bulky. It can hold any size cell phone, cash, cards, ID cards, keys and travel essentials. You can put these items wherever you feel most comfortable. Security pockets: The belt can be hidden under other clothing without being seen by others. You can still easily access it through the open pocket at the top so your belongings don't get lost.