First amateur upload: I have over engineered this great original creation but I needed a way to stop slipping off and over the knob when using it. Closed one end has a snug fit that wont slip off, the original design may be easier to use for some viewers so please see the original creator:

[https://www.printables.com/model/565555-next-level-racing-handknob-wrench](https://www.printables.com/model/565555-next-level-racing-handknob-wrench)