I just bought a couple new Filter Queens from ebay, and one of them came with a pack of Envirocare cones. I thought they felt lighter, so I held one next to a genuine under a light. The Envirocare cones let a lot more light through, so I threw them away and will use only the genuine cones. I did that on Tuesday of this week with brand new cones of both brands. That contrast doesn't prove that the others don't work as well as the genuines, but I don't trust them and don't want to find out the hard way with a vacuum as expensive as a Filter Queen.