The PrintrBot LC can be loud and shaky...this does a great job of reducing both of those. It could be even better with a little double-sided foam tape between the footing and the damper, but so far they haven't moved and the concept is a success.
Sketchup file added, to help any remakes.
I decided to get sticky-backed velcro, and cut small pieces to keep the feet in place. They never did come completely out, even after a lot of printing, but why take the chance. Soft velcro on the dampener side...hooks on the printer's feet (if it matters).
Really, this is pretty basic. The only additional suggestion I have is to squeeze it down once or twice after printing to ensure you've got good flex.