RAP-SB-275-45U: Composite 1 1/4'' x 2 1/2 '' Diamond Base Plate with .75" Snap Link Socket.
The plate has a hole at each pointed end and a socket for the Snap Link Ball at a 45 degree angle to the plate. The screw at the top of the socket can be tightened, once a Snap Link Ball has been inserted. The friction between the socket and the ball allows you to move the mount at this join easily while still holding the position you leave it in.
