So for starters I have a füm pipe but I always loose it. Been wanting a back up but it's really expensive. Mentioned it to my dad who pointed out the cores are about the size of old pipe filters. Now it doesn't work in every pipe. Alot were too big but this $6 corn cob pipe fit the core perfectly. So $6 for a corn cob pipe, $9 for a füm core pack and you could hmhive it a shot if you need something for hand to mouth sensation.