The product that controls: sweat, stains, and odor in any hat, helmet, or headwear item! Headline IT! is made up of three layers:1. The layer that touches your head- absorbs perspiration and wicks it into the liner, stopping it from running into your eyes. Headline IT! has been tested and approved for sensitive skin.2. The middle layer- even more absorbent than the first, pulling the perspiration and impurities into the next layer.3. The layer that touches the hat- filters our oil, salt, and odors. It breathes so the perspiration can evaporate, leaving impurities in the liner, NOT in your helmet or headwear item. Comes in a pack of 10.Each liner can be used several times! When it gets too dirty, just throw it away and grab a new one.