Features: Enhances your underwater communication with our diving cylinder impact balls, designs to produce a loud sound, ensuring your diving partner hears you clearly. Craft from quality materials, this underwater sound balls features a 44cm string and a 36mm diameter balls, providing reliable performances during your dives. Perfect for use in various underwater occasion, whether you're diving in open water or practicing in a swimming pool, ensuring your signal is alway hear. This innovative diving accessory is a must having for enhancing safety and communication, making it a essential addition to any diver gear collection. Great for diver of all grade, from beginner to experienced enthusiasts, who need a effective way to communicate while exploring the depth. Specifications: Materials: Rubber Color: As The Picture Shows Package Weight: approx.30g Styles Optional: 4 Styles is Available as Shown in the Picture. Balls Diameter: approx.36mm/1.41in (More Size Detail, Please See Picture.) Package Includes: 1Pc Diving Tanks Cylinder Knocker Banger Balls note: Please allow 1-3mm error due to manual measurement. Please make surer you not mind before your bid. Due to the differences between different monitors, the picture may not reflect the actual color to the item. Thanks!