With this 1" Ball Clamp Mark II for Lightweight Accessories, you can connect any 2 standard ball mounts with 1" diameters, such as those found on arms from Ikelite, TLC, Ultralight, Nauticam, and others. Designed for small lights and other accessories weighing less than one pound, the clamp features reduced plate thickness and a lightweight, three-prong wing nut. The minimized weight is also ideal for travel. The plates are spring-loaded for easy assembly and breakdown of your arm system. They are constructed from aluminum that has been hard anodized to resist corrosion.