Abstract: A door and locking system for a rear opening of a long bed trailer, the rear opening having a top edge, a bottom edge and first and second side edges, the door and locking system has a canvas door configured for mounting adjacent to the rear opening of the long bed trailer. The canvas door can move between a closed position in which the canvas door moves to close the rear opening and an open position in which the canvas door moves to open the rear opening. A locking system secured to the edges of the rear opening can move between a locked position, in which the locking system is in locking engagement with the canvas door in the closed position to secure the canvas door against the edges of the rear opening to close the opening for retaining fluidizable product in the long bed trailer and an unlocked position, in which the locking system is free from locking engagement with the canvas door to allow the canvas door to move into the open position.