A hook to restrain the movement of Bowden tube and cable on Ultimaker 2.
Version 3 features adjustable position for the hook. It also allows the tube to move in Y axis to reduce unnecessary bending. The length is slightly shorter than the spool holder.
Version 1 and version 2 has different position of the hook. 1 goes more to the left, and 2 goes more to the right.
Both v1 and v2 restrain the tube to the edge of the printer, which would create extra bending while the printhead reset to home position.