This part ships with the RAM-POD-I (RAM-316-1A). The female socket fits around a 0.5" dia. flex rod and uses a tightening screw to clamp the clevis in place. The other end of the post cap has a male Octagon Button that connects to the RAM female Octagon Button Arms.
(1) #10-24 x .75" Machine Screw
(1) #10-24 Nylock Nut