camping gas cylinder,can use in -20 around in the cold environment,application: picnic, travel, ... mixture 230g with propane/iso-butane, can use in -20 around in the cold environment. with a portable fire ... of the screw interface, so that the joint can open-top thimble of the wswitch. 3, and then joint-side ... edge of the switch to open a little twist, to ensure that no leakage, so ...