A shop drawing is a drawing or set of drawings produced by the contractor, supplier, manufacturer, subcontractor, consultants, or fabricator. Shop drawings are typically required for prefabricated components. Examples of these include: elevators, structural steel, trusses, pre-cast concrete, windows, appliances, cabinets, air handling units, and millwork. Also critical are the installation and coordination shop drawings of the MEP trades such as sheet metal ductwork, piping, plumbing, fire protection, and electrical. Shop drawings are produced by contractors and suppliers under their contract with the owner. The shop drawing is the manufacturer’s or the contractor’s drawn version of information shown in the construction documents. The shop drawing normally shows more detail than the construction documents. It is drawn to explain the fabrication and/or installation of the items to the manufacturer’s production crew or contractor's installation crews. The style of the shop drawing is usually very different from that of the architect’s drawing. The shop drawing’s primary emphasis is on the particular product or installation and excludes notation concerning other products and installations, unless integration with the subject product is necessary.