They are made by Ramco-engineering. Check out Ramco-engineering.com. Here is more info..
MSCSL12-QD. (Model #)
Scissor style extention for many viewing positions
Non-drifting design, even when at max load
Quick disconnect design for easy installation on and removal off the wall plate
Positive locking bumper for secure closed position
12-1/8" away from the wall when fully extened
4-1/8" away from the wall when fully closed
VESA Patterns: 75x75, 100x100, 100x200, 200x200
Max Load: 40lbs
Common Screen Sizes: 15"-42"
Full Spec Sheet
Hope this helps. This is the one in my heritage glen