The Yashica TL Electro-X is part of the TL series of SLR cameras. Production started in October 1968 and ended in December 1974. In 1975 Yashica moved away from the M42 mount and adopted their Yashica/Contax bayonet mount.
The TL Electro X is a significant milestone SLR, as it belongs to the first three SLR with an electronically controlled shutter, all introduced within a few months in 1968. In fact it was the only successful implementation. The other two were the Praktica PL electronic (more a technology study) and Zeiss Ikon's Contaflex SE (a complicated high end niche camera). Both only made it to about 3000 units, while the Yashica sold about 300,000 times!.
The electronics within the Yashica were combined with state of the art TTL metering and allowed step-less timing of the shutter at any intermediate speed between 2 seconds and 1/1000th. It was also the first camera with viewfinder electronic lights for exposure information (miniature lamps, not LEDs).
The Yashica TL Electro-X ITS was introduced in 1971, and sold alongside the first model. Externally the ITS differed by the monogram on the pentaprism being replaced by a gold-coloured "Atom" symbol. The ITS also came only in black, while the X was made in chrome and black finishes. Otherwise, the only identifiable differences between the two cameras were an increase of the x-sync speed to 1/125 on the ITS.