Waters SYNAPT G2 Operator's, Overview And Maintenance Manual page 49

1. Prepare the instrument for working on the source (see
Warning:
handle the ESI probe with care.
2. Remove the protective sleeve, if fitted, from the ESI probe tip.
3. Carefully slide the ESI probe into the hole in the probe adjuster
assembly, ensuring that the probe location dowel aligns with the
location hole in the probe adjuster assembly.
The ESI probe tip is sharp. To avoid puncture wounds,
ESI probe location dowel
Location hole in the probe
adjuster assembly
TP03129
page 5-7).
Configuring for ESI mode 3-3