RAM® Ball Adapter with 1/4"-20 Threaded Post - A Size
RAM A 9/16" Ball with Camera Thread

The RAM-A-237U, universal camera and camcorder base, consists of a 9/16" diameter rubber ball, connected to a 1/4"-20 camera thread. The male thread matches most standard camera and camcorder female threads found on the bottom of the camera.

SPECS

Ball Size:
A Size (9/16")

Weight Capacity:
.5 lb

Materials: 
Marine-grade aluminum

Weight:
0.04 lb

Warning!
Most people find that the "A" sized components work fine for holding a small phone in an aircraft or automobile.  However, I have received a significant number of complaints about the rubber balls detaching from the bases.  I therefore recommend the larger "B" sized arms for most soaring applications.  In fact, one customer temporarily lost control of his sailplane when his PDA cradle fell off the RAM A arm and jammed the control stick.  I have never heard of a RAM "B" size arm component failing.