Cal. 72 is a 14 ligne column wheel chronograph movement produced by Landeron (Charles Hahn & Cie.) in the 1940s and 1950s. It is part of a slightly-larger family of cam-switching chronograph movements less well-known than the famous and innovative Cal. 48 family. The various Cal. 71 family movements are similar, differentiated mainly by changes to the cam mechanisms, bridges, and plates, but Cal. 72 is unique in that it uses a simple three-column wheel rather than the cam plates used by all others.