Dedicated to gitzos systematic tripods the gitzo gslvls systematic levelling base allows quick accurate levelling when setting up a shot and is especially useful when shooting with a flat base video head or in landscape photography a head can be attached onto the 38 screw of the levelling base and the lever on the side tightens the screw securely against the head the gslvls base is compatible with any systematic tripod via the optional 75mm video adapter gs3321v75 for series 3 and 4 tr