Over the hook. If the needle is punching up-and-down it can actually hit this area and depart a mark. Particularly when the machine will not be in excellent sync. The duo Brush Machine liftsthe carpet pile making certain all surfaces with the fiber arecleaned, leaving your carpet revived and softer. http://sebo-vacuums-boulder91234.ivasdesign.com/20012075/the-best-side-of-boulder-vacuum-bags