(From company literature) Manfrotto 3416 Leveling Base. The 3416 Leveling Base head enables the operator to make fine, finger tip adjustments of +/- 5 degrees to ensure the camera is perfectly level. All three platform adjustment thumb wheels are provided with a locking ring to assure stability once the right position is reached.
There is also a built-in spirit level for reference and the base has a 3/8" female thread to mount on a tripod or any other support. Camera head mounting is via a 3/8" male screw.
• Spirit level with a sensitivity of 0.5 degrees.
• Three thumb wheels rings for fine level adjustment.
• Three set screws located on top plate of base to lock camera head firmly.