Aluminum ball with standard 1/4-20″ threaded stud, and locking thumb nut. Fits camera tripod sockets such or any camera that has a threaded 1/4-20 attachment point. Use this adapter with any Rock Steady ball mount knuckle or the Robinson Tow Ball Mount.
The Rock Steady V-block is quality all metal machined aluminum. The 90 deg V fits any size aircraft spreader bar, bi-plane strut, or wing strut from a J-3 to a Caravan. The flat side of the block has two 1/4-20″ threaded holes.