The Copal #3s Shutter is a high performance, manual cocking shutter.
The shutter release lever exposes film or digital sensor after you close the view lever and cock the shutter. Click-stop lever controls shutter speeds from 1 to 1/125 second, plus "Bulb".
Note: f/stops are not calibrated, and their positioning depends on the lens that is to be coupled with the shutter.
The flash sync terminal is standard "PC" type.
Requires rear retaining rings and basic f/stop calibration instructions for your particular lens