It depends on which stove it's for. The smaller ones have a plastic tube available. You can also order a Caldera Kitchen from AGG. It includes a stuff sack so you can pack all of your stove, cone, etc into one bag. I use the stuff sack for my Snow Peak 900. My Brasslite 600 holds a cone with a plastic cup over the top of it (upside down).
See AGG's offerings: