This is a Stainless Steel Oil Line -3 Female JIC to Banjo 6.75″ for a National vacuum challenger 607 pump. This part fits all National Vacuum 607 PRO Challenger Series vacuum pumps.
This is diagram part #59 on the 607 PRO fan cooled pump exploded view and diagram part #54 on the 607 PRO liquid cooled pump exploded view.
The National Vacuum Equipment Part Number is 320-407-005z






