Features: 1For Emergency: This whistle can be used when you are in an extreme environment or an emergency, and the effort to whistle can be reduced to seek help. 2Convenient and Practical: The emergency whistle comes with reflective cord and adjusting buckle, which can tie on your backpack or belt. 3Durable Material: This set of emergency whistle is made of plastic, which is very light, waterproof and durable. 4Double Tube Design: With dual tube design, each whistle can produce high frequency and low frequency sound. 5Widely Used: This kind of survival signal whistle is very suitable for diving, camping, hiking and other outdoor sports. Item Type: Material: Plastic Weight: Approx. 100g/3.53oz Specifications: Orange, 10x reflective rope, 10x adjusting buckle Package Included: 10 x