This is the Sea & Sea Sea Arm 8 Ball Clamp for Underwater Housing Strobe Features: Designed for universal use with compact digital cameras or SLR systems/li> Machined from corrosion-resistant aluminum/li> Anodized coating for enhanced protection The Ball Clamp is used to attach to ball joints such as a double ball arm or base/tray [Dimensions (WxHxD)] 65x67.5x25mm / 2.6x2.7x1inch [Weight] 67g / 2.3oz [Construction] corrosion-resistant aluminum alloy (anodized body) he Sea Arm 8 is designed for universal use with compact digital cameras or SLR systems. The Sea Arm 8 components are machined from corrosion-resistant aluminum and carry an anodized coating for enhanced protection.