Butane gas canister 250 gram each To maintain constant high pressure specially for brazing purpose, the composition of our gas in 250 gm. canister consists of approx. 5% of propane, 80% of ISO-butane & 15% N-Butane. Quality & safety of our canisters fulfills EN-417 and UN-2037 Certification. Our products are Korean and have been made by the Robotic plant, without any human involvement on production line. We have two different categories of canister, one with High Pressure which contains 250 gm. with heavy gauge tin plate walls & 250 gm. canister with normal LPG.