The RAM-B-349U includes a M10 x 1.25 pitch male thread connected to a 1" rubber ball.
Compatibility:
Threaded hole must contain the following dimensions for this base to fit: M10 1.25 pitch with a 14.5mm flange diameter with a 10.15mm thread length. - See more at: http://www.rammount.com/part/RAM-B-349U#sthash.WSOsRqlZ.dpuf