A notice board or pin board is a board that can be attached to a wall to display notices, messages, adverts, and bulletins or to keep notes or reminders. They are often made of cork or felt with an aluminium or wood frame. Metal notice boards are also available which can be used outdoors in areas such as car parks. Some notice boards have a combination of surfaces having both a blackboard and whiteboard, or a magnetic dry wipe board and felt board. Another product that can be used to display notices is a wall mounted document holder and frame. A document holder is smaller than a notice board and is used as a wall display for information such as notices, health and safety information and certificates.