This thing is wire terminal that I used for connecting speaker wire to a radio. It uses small (1 1/4") alligator clips. Speaker wire from the radio are soldered to the alligator clips and clips inserted into the clip holder. Press the top exposed part of the alligator clip and insert the wire from the speaker into the hole in the bottom of the clip holder. I have included the Fusion 360 design file if you wish to make mondifications.
Solder wires to the alligator clip before inserting the clip into the clip holder. Run speaker wiring from the radio through the slot and solder the wire to the alligator clip. Now insert the alligator clip into the clip holder. It should be a tight fit, I used a smll screwdriver to press the clip in all the way. I put a small peice of colored heat shrink on the exposted clip to mark the polarity of the terminal.
To use, press the exposed end of the clip, and insert the speaker wire into the hole in the end of the clip holder.