The material does feel a little like paper, but it doesnt bother me. I dont know if thats an issue of the package being in shipment "limbo" for so long, or if it was due to bad seals on the bottle. When I first put them on, I thought "oh no, they dont fit". Perfect for what I had in mind! but I can?t help but wonder if perhaps they were putting the cap on backwards? Idk? Worth a try anyways if you ask me. I hung bag up on my hook, about 3 hours later I noticed the top of the case had fallen off. Came well packaged The slipper basically split in half after 3 months of use and I had to just throw it away (see pic). I ordered this so we could use it to charge our phones and tablet in our camper off the cigarette lighter style plug. If I use my road bike with slick tires (so pretty much no tread), its whisper quiet.