The Gitzo GS3313GS Systematic Gear Center Pole is an accessory that incorporates into the systematic tripod for even higher shooting and quick and accurate height adjustments.This aluminum geared center pole is compatible with systematic tripod, 3 and carbon 4.The gear mechanism allows you to raise and lower your heavy camera equipment with a thumbscrew lock for easy locking and unlocking.With a safety catch and when used in conjunction with the modern systematic tripod with safety button, the accessory will not come off accidentally even if you forget to tighten the lever on the tripod side.The GS3313GS is the successor to the GS3311GS and has been updated with the upper and lower end of the center pole.