Triton T300si Installation And Operating Instructions Manual page 23

Apply PTFE tape to the threaded connector.
Screw the bulkhead assembly onto the threaded
connector until tight to the wall and the two
fixing holes are aligned. Secure to the wall with
the two screws supplied (Fig.).
Finish by clipping the cover onto the bulkhead
making sure the protruding legs locate in the
bulkhead body.
T300si wireless remote electric shower

Fig.
Fig.