443C heavy duty cutting attachments are machined from high quality die-forged brass for durability and stainless steel components. 442C featuring a flat seat tip design and an in-head mixer, have three tubes in a triangular arrangement. Its stainless steel tubes for strength & long life and stainless steel oxygen lever for durability, spiral mixer gives optimum mix of fuel & oxygen, and brass coupling nut and double o-ring seal gives quick, hand tight, & leak-free operation.