ISO50

“The Olivetti Lettera 32 is a portable mechanical typewriter designed by Marcello Nizzoli for Olivetti in 1963 as the successor of the popular Olivetti Lettera 22. This typewriter was popular amongst journalists and students.
The typewriter is sized about 34x35x10 cm (with the carriage return lever adding about 1-2 more centimeters in height), making it portable at least for the time’s standards, even though its 5.9 kg weight may limit portability somewhat.”
– Wikipedia