The RAM camera base contains a 1.5" rubber ball that is connected to a 2.5" diameter round base.
Also, included is a 1/4"-20 threaded steel stud, centered, the round base provides support and
stability for cameras that rest on top of it. The male 1/4"-20 threaded steel stud will connect
to any standard female thread found on camcorders and digital cameras.
4-Hole AMPS: 1.181" x 1.496"
3-Hole 120-Degree: 1.812" Diameter