The RAM-B-273 is supplied on a hexagonal with  1/4" - 20 thread hole plus a longer thread stud.

This is often used to achieve a single ball post mount on some motor bikes.

Another use for the RAM-B-273 to replace the bolt on the RAM arm (RAM-B-201) where the RAM-B-273 provides a way of providing a second mount ball for an additional device, as shown in the inset photo.

When ordering this part, please make sure you also order the relevant base/arm mount/cradle to give you the complete solution. A selection of different mounts to attach to cradles is shown below and these will fix to the any cradle you may have which has a diamond socket.