441-line television system
441-line is the number of scan lines in some early electronic monochrome analog television systems. Systems with this number of lines were used with 25 interlaced frames per second in France from 1937 to 1956, Germany from 1939 to 1943, Italy from 1939 to 1940, Japan in 1939, as well as by RCA in the United States with 30 interlaced frames per second from 1938 to 1941.
Source: Wikipedia — 441-line television system (CC BY-SA 4.0)