image by Daniel Lévesque (Image rights)
The CT-20 is an SLR for 35mm film introduced by Cosina circa 1980. This is a rather no-frills model offering only aperture-priority autoexposure as its sole exposure metering option. There are no manual shutter-speed settings available, besides "B" and the X-sync speed of 1/100th second; and the metering display is simply a few LED "stop lights" which do not indicate what shutter speed will be selected. The electronically-timed, vertically-traveling metal shutter ranges from 4 to 1/1000 seconds and requires power from two 1.5 silver-oxide batteries.
Compared to the CT-10, a model which otherwise is quite similar, the CT-20 adds a backlight compensation button; and a self-timer with a blinking countdown LED on the front of the camera. There is no provision to attach a power winder, and no PC socket.
The camera's hot shoe has an additional contact, which when attaching an appropriate dedicated flash (Cosina Auto-160 or Auto-220) can force the camera to its X-sync speed even when set to "auto"; also lighting an "F" in the viewfinder when the flash is fully charged. The manual states this can be confirmed with an audible tone with a half-press of the shutter release.