Core consists of Teflon (polytetrafluoroethylene) with two outer reinforcing jackets of stainless steel braid (Teflon is inert to most chemicals and solvents, except molten alkali metals and fluorine at elevated temperatures and pressures)Teflon withstands temperatures from -65° F (54° C) through +450° F (232° C)Minimum bend radius of 3 inches provides for maximum life and safe performanceAll pigtails 100% tested before shipping and labelled for gas service and pressure rating