Made of food-grade 304 stainless steel. Each whistle comes with a soft braided lanyard for hands-free use. You can use it anywhere you need to get others’ attention quickly. There is a cork pea in our whistle. Our cork pea is made of natural large wooden cork, which is different from synthetic pea. When you blow it, it vibrates at a higher frequency, causing the whistle to emit a louder sound. It can reach up to 120db quickly.