1.High quality stainless steel outer pipe, PVC anti-burst inner pipe. 2.Anti-corrosion and with high temperature resistant. 3.Thickening nut and copper core interface provide solid protection, refused to crack. 4.Silicone sealing rings, non-toxic and tasteless, prevent from leakage. 5.Standard G1/2 inch interface, about 2cm in diameter, is suitable for the majority of families.