Ok folks. On your suggestion, I purchased the Optimus Primus Optifuel stove. I have seen some brass adaptors that screw into the stove where you would normally screw in the butane canisters. These adaptors allow the stove to use the 1 pound bottles of propane in addition to the other fuels. I see some of these adaptors have some type of safety valve inside them, and some do not. Do you guys have a link for the safe ones? Thank you, MikieG