The torch is self-igniting, meaning it has an electric sparker built in. When the button is pressed halfway, the torch mixes a perfect combination of propane and air into the tube. When the button is fully pressed the torch sparks sending a flame flying through the tube. I tried to color the flame with some boric acid, and it turned bright green. Well this experiment was not explody enough for me, so I used the same concept to build a propane powered cannon. This is honestly the best gas cannon I've ever used, it is just so simple. You could probably shoot 20 golfballs a minute the length of a football field or farther. The canon shot golf balls over 600 feet in the air!! One important thing I forgot to mention in the video is the fit of the object in the barrel. If you completely plug the barrel the gas mixture does not enter the tube, because torch only 'passively' blows the mixture down the tube into the combustion chamber. All the projectiles i shot had some 'slack' in the barrel.