Mounts to Ikelite's Quick Release Handle for attachment of 1-inch diameter ball arms from Ikelite, TLC, Ultralight, Nauticam, and others. Requires a compatible 1-inch Ball Clamp, sold separately. The 1-inch Ball Arm System Mark II features 1-inch ball components with a groove and o-ring to prevent slippage for improved holding power with less force. While underwater, clamps may be finger-tightened to keep lighting in place yet allow repositioning without loosening the clamp. All parts are hard coat type III anodized for a long lasting, scratch resistant finish.