Airflow Design: With great airflow design, it can easy to whistle and make a loud, clear sound. Material: The plastic is safe and durable. It can be used for swimming in various seasons of spring, summer, autumn and winter. Portable: Compact size and portable mode, you can hang it on your bag or the key ring, very convenient to carry. As a Gift: An indispensable accessory for outdoor sports lovers and a unique gift to you friends.
