... PTFE diaphragm 2:Flexibility strong 3:stand strong collision 4:customized 5: diaphram with rubber,long lifetime Features: MaterialNBR,HNBR, MVQ, NR ... set, high temperature resistance, low temperature resistance, ozone resistance... )Color black, red, white, green, yellow, blue, brown, according to customers ... , can develop most kinds of high tech required molds. Black rubber diaphragm with good quality