We have a vertical wind tunnel (not Hoover brand but uses Y-bags). I've been looking for cheap bags since the beginning of spring. We have a cat and as every cat owner knows, she sheds a lot in the summer. Not only are these bags inexpensive, they also work great. They fit perfectly and gave our old (jammed) vacuum a new lease of life. I think I'll buy another bag in case these go away. I am absolutely satisfied with my purchase :)