The butter tins are quite a bit larger than you might think. This doesn't help though since the waterproofing is achieved by a large rubber / plastic insert which takes up a bunch of room. Further they are truely bomb-proof! They are made of very thick aluminum. I can't imagine actually carrying one in a pocket due to the wieght and the size but There may be reasons to use them. I can't imagine one now but If anyone does let me know. I don't need butter on my hiking badly enough to stick one of these in my pack full of butter - that much is certain.