Abstract: An arrangement to releasably secure each of the two doors of a utility carrier box mounted transversely behind the cab of a pick-up vehicle and on the side walls of the pick-up, the arrangement comprising staples secured to the end walls of the box below the end flanges of the doors when the doors are in closed position, and a steep strap extending from below one staple, over the top of the closed box and down to a point beyond the other staple, and in conformity with the surface of the closed box over which the strap means extends, each end of the strap being slotted to enable the link of the staple beyond which it extends to be passed through the slot and to receive the link of a padlock which is locked.