Our trailer has what I call butterfly doors on the back. It has two handles one on each door. You lift the handle up and pull the door toward you. Then when you close the door you push the handle down and it goes into a hole at the bottom of the trailer and locks into place. Then I have a chain that goes into a little loop. For the goose neck I have two heavy logging chains that I hook to the hooks on my fold down hitch in the bed of the truck.