Features: Can smoothly swivel up to 15 at any direction. Design for precise leveling of tripod heads, video ball and panoramic heads. CNC constructed aluminum alloy body, flat and compact design for high stability. Built-in bubble level ensure precise alignment. Top 3/8 screw can attach to most photographic head. Bottom diameter 6cm, 3/8 thread; comes with a 3/8 to 1/4 convertible screw. Mini size, with carry bag, quite portable.