Zone 3 Safety Swim-Run Compass and Whistle Bungee Combo | 2021 This combo is ideal for long distance swims as it is accurate and durable. It will keep you safe and help you navigate your session with ease. It is waterproof and made to last a life time! A finger grip design on the side makes this combo easy to use in cold water. Due to the whistle being made from polypropylene material the whistle will float and not corrode! A great combo to ensure a safe journey through the water! Features Waterproof Light Weight Finger Grip Metric and Imperial Rulers on the sides.