Knottology Banshee Expedition Clasp - Black - The Knottology banshee is one of the high-test quality whistle ever created. This extremely loud whistle offers a high pitch sound with very little effort. Perfect for when out in nature; jogging; or for children. Our 100 decibel whistle is the first of its kind with its sleek design and all metal construction. The nose flute is perfectly adjusted to create the perfect pinch. All metal construction. Choose from Silver; Gun Grey; Black. Extreme High Pinch Metal Whistle (Approx. 100 Decibels). Rugged 4/8 inch Metal Spring Assisted Side Release Clasp.