That is the same as my fish trap, but mine has a sliding door (up and down) with a thin piece of plastic wire attached to operate it. It is easy just to drop the door down when fish are inside. As I've said elsewhere, I also use it to introduce new fish. I put them in the trap and leave the door closed for an hour or two. Then I open the door and the new fish is free to swim out, but they have the added safety feature of being able to return to the box if threatened, and the established fish stay away from the box as it's 'new'.