I don't know how good they are because Shark doesn't seem to want people changing any of the belts on their new vacuums. After several trips looking for the right screwdriver to open the belt compartment, my husband contacted the shark and was told not to try to change the belt! They had us send them a vacuum cleaner and they sent us a replacement. They said the straps wouldn't snap. Let's see how long a replacement vacuum lasts. I'm not sure I'd like a vacuum that can't be replaced with a belt.