it is a slotted sleeve attached to suction cup - a tension-type sleeve to hold knife in place.
The sleeve can range from 1" to 2' wide with the opening (slot) the thickness of the knife blade. The sleeve/slot is attached to the suction cup and the unit can sit very stable on the counter top to store knife safety when cutting cheese, etc.
Problem this idea/invention addresses:
It allows you to store knife safely while using the cutting board.