Olivetti Lettera 22 - tab stops

Tab stops on an Olivetti Lettera 22 typewriter. The round metal bar on the underside of the carriage has a row of needles, of which some are extended. These needles form the tab stops, and can be set or unset by using the tab stop set lever (on the left of the keyboard). The tab key lets the carriage move to the left until it hits a set tab stop.