Lowrance 16i Installation Instructions Manual page 7

Insert mounting rod through swing arm's socket, as shown.
4. Snap the red rubber adjustment lock onto the rod and screw it into the
swing arm's threaded socket. As the lock is screwed in, it tightens on the
mounting rod, holding it in place.
Snap adjustment lock onto transducer mounting rod as shown, then
screw it into the swing arm's socket.
If it is too hard to turn, consider adding a small amount of petroleum jelly
or silicone lubricant to the threads on the adjustment lock. This will help
the lock turn more easily, which may be necessary in very cold environ-
ments.
5. Slip the assembled transducer rod and swing arm into the ratcheted
swing arm socket on the front of the base plate.
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