This is a ROV cover or shroud that you can use on your ROV in underwater robotics competitions and here are the instructions on how to assemble it INSTRUCTIONS

YOU ARE GOING TO NEED TO USE TWO SCREWDRIVERS TO TAKE OF THE PROPELLER AND THEN SLIDE THE SHROUD ONTO THE MOTOR THEN (IMPORTANT) GET A NEEDLE NOSE PLIER TO HOLD THE PROPELLER AND THEN POSITION IT IN THE SHROUD THEN BRACE THE MEDAL PRONG AND THEN SCREW THE PROPELLER ON AND YOUR DONE.