Clip on feet for backpacking isoPropane canisters. I use these feet to level / stabilize the canister when using the stove on uneven or sloping rock. It can also be used as a separator between the canister and pot when packing, at least with some combinations (do not use as a separator with non-stick pots, it may damage the non-stick surface).
A stabilizing version for flat ground can be found at : http://www.thingiverse.com/thing:210916
I would recommend printing with a flexible plastic like PET, I'm not sure it will work with other plastics.