For a better view here are the hockey pucks I make for the Monaco swivel levelors when used over carpet. They are a 3 1/2 X 3/4" plywood disk with a recessed inset for the adjustable base.
On the bottom of the disk I fasten a 3 1/2" round disk cut out of plastic office chair protector with the plastic nipples which are set into the carpet nap. This makes for secure positioning.
With the legs firmly embedded in the carpet and fastened to both the cross members and longitudinal stringers, a free standing peninsula can be held steady.
Typical installation
