Object permanence is the understanding that whether an object can be sensed has no effect on whether it continues to exist. This is a fundamental concept studied in the field of developmental psychology. You can read more about it here: https://en.wikipedia.org/wiki/Object_permanence

This infant toy is a rounded version pattered after the Montessori Object Permanence toy. The little kid sits next to the toy and picks up the ball then drops it in the hole. Kids at the right stage in development are thrilled with this toy and do it many times in a row. Apparently their brains need the repetition to learn what is going on.

On Feb 12, 2026, these files were updated to make the ball bigger for safety. It is now about 1.8 inches wide and the hole is larger also. The old files were deleted.

Print using supports. No assembly required.

Version 1 square
Version 2 rounded (this page)
Version 3 tall spiral
Version 4 taller spiral with slot window