FujiFilm EN-580T Operation Manual page 67

(7) Feed air to inflate the balloon on the distal end of the
endoscope, and stabilize it within the enteric canal.
(8) Insert the Over-tube into the body cavity along the
endoscope to a point close to the balloon on the distal end
of the endoscope.
[Note]
There is a thick line (indicator) on the insertion portion
of the endoscope. When the Over-tube is inserted into the
body or the endoscope is pulled out from this position, the
tip of the Over-tube touches the balloon.
(9) Feed air to inflate the balloon on the Over-tube, and
stabilize it within the body cavity (small intestine).
Chapter 6 Method of Use
6-7