Complete with control knob Viton® O-rings on PTEF shaft are protected with two precision Teflon® wipers (or as shown in the second picture O-ring is inside shaft) The plug has a machined-in integral PTFE tip O-ring to make the primary seal This design provide for an excellent vacuum tight seal without exposing any material other than Teflon® to chemicals Description: 0-8mm vacuum metering plug and control Valve ( O-ring is inside shaft )
