I may be wrong but aren't these the ones that are more of a thin plastic like plastic bag material rather than a more rigid normal plastic tunnel Where it's just plastic if I remember rightly do t these have wire to hold them. I'm not making much sense but what I wean is aren't they sort of a floppy thin plastic sheet material apposed to Something like this
http://www.zooplus.co.uk/shop/small_pets/accessories/tunnels/118659
I'm just trying to remember because we had one for the dryer or something but then again it may be perfectly safe for buns anyway :?