ITEM NAME:8" inch Double Ball Arm Segment for Diving Underwater Housing Arm System Black Description: Lightweight, highly durable double 1" ball designï ¼Å’with non-slip rubber ring Made of high quality carbon fiber and aluminum material, durable to use. Super light carbon fiber with double ball design, can keep the arm buoyant. This float arm is both for macro and wide-angle photography. Application: for shooting water-activities photos, or diving under water. Specification: Item : Camera Underwater Float Arm Material: Aluminum Alloy, Carbon Fiber Features: Durable, Easy to Install, Waterproof, Camera Supplies Diameter: 20.8mm Length: 8 inches Package Includes: 1 x Camera Underwater Float Arm (Others Not Included).Application: for shooting water-activities photos, or diving under water. Super light carbon fiber with double ball design, can keep the arm buoyant. Lightweight, highly durable double 1" ball designï ¼Å’with non-slip rubber ring.