Gitzo Series 3 Carbon Systematic Rapid Column Sigma SA Mount With a constant F2 With a constant F2 The tripod is carefully matched with a GH1382QD Center Ball Head engineered and designed focusing on ultimate smoothness and precision of the movement and locking 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 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