Gitzo Series 3 Carbon Systematic Rapid Column Full Frame captive locking T Knobs and captive captive locking T Knobs and captive collars the lens’ magnesium body ensures high mobility and its dust and splash proof structure together with the water and oil repellent coating on the front element ensure safe use even in the most challenging shooting conditions The rapid column slides freely and quickly in the tripod shoulder and is locked and unlocked via a simple twist mechanism offering the same strength and solid locking under heavy loads The safety catch feature when used together with recent Systematic tripods with a safety button prevents the column from dropping out of the tripod even if it is inadvertently left unlocked