Line printers have a spinning horizontal drum that stretches the full width of the paper which is separated from it by an inked ribbon. The drum is made up of 132 thin cylinders each having a complete set of characters. Behind the paper is a row of 132 hammers that strike the paper at the right moment to select the required character from the corresponding cylinder. In this way it is able to print a complete line at a time. Line printers are used for high volume low quality output and are very noisy. They are obsolete now.