1、Free Extension: The connector ball head extension supports to connect strobe or video light. Freely adjust the angle to get the best light angles to take the best photo you want. 2、Hollow Design: The hollow design makes it lighter and reduces resistance when used underwater. The weight is about 5oz (70g), the buoyancy almost completely offsets its gravity. 3、With Protection Ring: The ball head is made of corrosion resistant anodized aluminum alloy with O ring friction gaskets, avoiding friction during connection and making the connection more stable. 4、Adjustable Length: The product adjustable length is about 15‑20cm / 6‑8in arm as a bridge to connect underwater tray or handle to underwater strobe or video light. 5、Underwater Use: Humanized and professional design greatly improves the use of the lamp arm underwater. Extend the diving light arm to connect multiple diving equipment (such as fill light, buoyancy arm, etc.). 1 x Dual Balls Arm Item Type: Dual Balls ArmMaterial: Aluminum AlloyProduct Adjustable Length: Approx. 15-20cm / 6-8in Weight: Approx. 70g / 2.5ozBall Diameter: Approx. 25mm / 1inThread: 3/8 (middle) 1/4 (both sides)Features: 1. Aviation aluminum, professional diving high strength hard anodized arm can prevent seawater corrosion. 2. Sturdy, lightweight, waterproof aluminum structure. 3. Use the ball arm between a ball clamp to extend the arm. 4. The unique humanized and professional design greatly improves the use of the lamp arm underwater. 5. Extend the diving light arm to connect multiple diving equipment (such as fill light, buoyancy arm, etc.).