1.used to a larger low-chromium cast, 2.very simple 3.high-yield. Features,It can be used to a larger low-chromium cast,very simple and high-yield. Istuction,1,Before use,it shoule be protected with acetylene through spraying smoke or high-temperature coatings.2.It should be clean up and protected again after using.3If not used for a long time, can use waste oil to protect,so that can extend the ...