Used to give a visual indicator that bed leveling is turned on for an Anycubic Kobra Go You can watch the z axis movement during each level of print and see the pointer move back and forth to match the highs and lows of the bed. The pointer being off center of the z axis rod amplifies the movements, making it easier to see at a glance that the bed leveling is on. Sizing may vary depending upon how well tuned your printer is. No internal threads, but sized so that I threaded onto the z axis threaded rod. If you need it a little tighter or looser, just use the sizing tool on your slicer. I printed it 100% solid. Don't worry it doesn't even come close to the filament that is being fed. Video of it in action https://www.youtube.com/watch?v=OZeYlyyh1Xk

Sorry folks, had to revise the design. When the filament roll gets low, the pointer would grab and wind around the Z axis rod