"Since I helped to create our field of Assistive Technology back in the early 80's, we have been looking for something that can:

1) Hold something *very* firmly for the user.
2) Be infinitely positionable.
3) Yet be able to be removed instantly and attached to something else." RJ

More...

Device Adapter (for Arms and Tall Tablet Stand)

The combination of the Device Adapter and rectangular Universal Base seems to be a nice solution. You can attach the Base to just about anything, keyboards like our BIG Blue keyboard, an AAC device from PRC or Tobii-Dynavox, or a tablet PC that is over 4 lbs. (if your device doesn't have a flat area of 8" x 5" on the back, then select the 'small Universal Base' with a 4" x 4" footprint)

The Device Adapter screws into the end of one of my Arms or the Tall Tablet Stand.  The Base 'super'-VELCRO's® (BRAND) to the back of your device. And the Device Adapter and the Base mate very securely, yet can be separated in an instant.

A variation on this is my Base with screws/holes for the iAdapter series of cases.