1.easy to operate and quick to turn on/off.2.three sealing is reliable to improve safty and life.3.the PTFE can use from -20 degree Fahrenheit to 300 degree Fahrenheit.pressure class from 150 to 600.4.It can wipe off any residue or particles adhering to the plug.They also protect the sleeve from erosion,prevent cole flow deformation,and eliminate sleeve rotation. 5.Under work condition it can adjust the primary stem seal.