While retaining the potential of the "Flex Arm'', by adding a locking function, the frame can be locked without accidentally opening even under windy conditions that are essential for sea bass games. Even if you hang it on a net or put it through your waist belt, it is locked and will stay in place when not in use. The locking mechanism can be released with one push, so you can set it up with one hand without stress even when it is caught.