1) Brass with good nice nickel plated. 2) BSPT thread (British Standard Taper Pipe Thread). 3) The thread part of the fitting is longer and more thick than many other supplier of China. 4) Sleeve with black color. 5) Each and every pcs was tested at 10kgs/cm2. 6) Thread with teflon coating which can seal directly without any other seal material. 7) Bottom was hexagonal suitable for fitting by lkey. 8) Chipware is copper with nice nickel plated. 9) Inner seal can bear 75 degree 10) The snap spring is stainless steel with heat treatment and the life time is more than 1000 times.