If you look in you HOOVER owner's manual,
I'll wait while you get it out of the top drawer of your desk, along with other important documents.
......... OK? Good.
Let us all turn to the page about bags. . On page 14 of model # U4101, 1976 manual ( the copy I'm using now), What bags to buy: "To assure that your HOOVER cleaner operates at peak performance, it is imperative that you use only genuine HOOVER throw away bags, made by The Hoover Company."HOOVER bags can be idetified by the trademarks........ There's also advice on the back cover page from The VCMA, consumer information, telling basically, the same thing.
It's awful when you go to, say ,Walmart, to purchase a HOOVER cleaner. But, Walmart doesn't sell GENUINE bags!
They only carry Enviracare or ARM&HAMMER bags. What is one to do?
The only thing in my house made by ARM&HAMMER is baking soda, known for years as salaratis.
So, let us follow our manuals and enjoy years of problem-free cleaning w/ our respective genuine replacement bags Works for me!