This bowden tube clip fits over one of the screws so it can swivel for quick and easy access to the tube, without the risk of loosing the clip, which has happened to me more than once :) Thing files include three versions of the clip of varying thicknesses a 1.0mm, 1.5mm and 2.0mm. I'm useing the 2.0mm version on my printer as it eliminates any tube movement when alternating between extrusion and retraction.