To use the weatherproof connection over, firstly run the input and link output (where used) cables through the glands.
Trim the cable ends to fit into the loudspeaker's Euroblock connector, without leaving excessive exposed conductor, as this can easily short the two cores together. Doing so will cause your amplifier to protect itself, and no sound will come from the loudspeaker.
Be sure to observe correct loudspeaker polarity.
Where present, make sure you have the correct tapping selected from the rotary control beneath the input connector (see Cuboid - Transformer Taps). Then push the cable mounted connector into the speaker, and slide the cover over the cable until it fits against the recess in the back of the speaker.
insert the four screws to secure in place, tight enough to seal against the cabinet but not over tight.
Finally, tighten the cable gland onto the cables(s) to provide a good seal. If only one gland is used, tighten the second as far as you can.