Suggestion Box Safco's Suggestion Box is a steel suggestion box that can also serve as an office drop box, deposit box, prize/drawing box and more. With a 4 ¾" x ⅛" deposit slot, the suggestion box has a durable, black powder coat finish. Suggestion Box includes two keys and front panel adhesive labels, as well as 25 suggestion cards and wall mounting hardware. For additional suggestion cards, view the Suggestion Box refill pack (4231).