An enclosure which houses electronic equipment. Can be large or small, portable or fixed, wall, desktop, or floor mounted. Standard width is 19" (outer mounting ears of equipment). Usually measured in spaces or rack units with one space being 1.75" tall. Rack names are usually given based on the equipment housed in them (i.e., amp rack, effects rack, patch rack, etc.). Almost all professional equipment can be mounted in a rack (though it may be an optional accessory) and conforms to the above measurements. Many different types of doors, shelves, drawers and other pieces are available that mount in racks.