The Yashica Mat-124 was made up until 1970. It is based on the similar Yashica-24 and Yashica-12. The replacement Yashica Mat-124 G was made from 1970 till 1986 and was the last TLR produced by Yashica. Even if this type of camera seemed to be obsolete at the time of its appearance, the 124 G was a success.
Both models have a four-element, 80mm f/3.5 taking lens, of the better "Yashinon" variety. The Mat-124 and Mat-124 G (Yashica-12, 24) all accept Bay 1 accessories, such as those made for the Rolleiflex. Focusing is via a ground glass screen, with a 3x diopter loupe for critical focusing, as well as a sports finder. The focusing screen is used with the camera at waist-level. (Camera-Wiki.org)