The transom mount motor prop head goes into where the open space is visible and clamps to the wooden mount that is visible in the picture. The battery goes in the pocket visible on the other side of the space. This pictured floating tube unit then attaches to the SEPARATE tube or toon where the rider sits with some kind of attachments or straps. There should be control wires or a remote that goes to where the rider is sitting in the separate tube or toon for on- off control. That's the general idea, I never did see or use one myself, just remember the online pictures.
Hope this helps.
You will need to turn the head 180 on your motor so the the handle and the propeller are facing the same direction.
You will need to strap it tight to the sides of your tube.
You have to put the motor in first then the battery box.
It has to pull you. Steer with your fins.
I did this for one season, the second season I bought a U tube. Much better then a Super Fat Cat.