Waters SYNAPT G2 Operator's, Overview And Maintenance Manual page 118

5. Using the combined 2.5-mm Allen wrench and cone extraction tool,
loosen the 2 captive screws that secure the ion block cover plate.
6. Remove the ion block cover plate.
7. Grasp the isolation valve and pull it out of the ion block.
5-40 Maintenance Procedures
Ion block cover plate securing screw
Ion block cover plate
Isolation valve
O-ring