I just want to say, I received these today for my Sanitaire S647 and these are definitely genuine. They came in a 2 pack Eureka bag...not the garbage, bulk generic ones! I've used these before and the ones from the vacuum store as well as bulk generic ones from Amazon. There IS a difference! The genuine belts last literally 10x longer! The generic ones would shred/snap in a couple weeks. It wasn't just a bad belt or 2 either....I went through 6 in 2 months!! There IS a difference in belts. Pay a little more and they last much longer.