The Large Leveling Base from Acratech is similar to the company's other Leveling Bases, but with a larger-diameter surface (2.9"/74mm) to ensure that its spirit level will be readable even with larger heads mounted to its 3/8"-16 stud.
Allowing 10° of movement in any direction, the Large Leveling Base has a 3/8"-16 thread at its bottom for mounting on professional tripods.
This Large Leveling Base is especially useful for creating stitched panoramic images that require an absolutely level base for your ball head.