This is a larger foot for the kid's version (but it may fit the standard version as well, I have heard mixed reviews on that front) of the Ikea POÄNG chair, so that the chair is less like to flip over forwards. My toddler likes to sit on the very front of this chair and it has a tendency to flip over. These feet extend the front of the chair so that it is much more stable.

It should be printed on its side for strength and does not require supports. To install, simply unscrew the existing black feet and reuse the same hole and screw to install the new feet.