Zorki (unofficially known as Zorki-1) was the first model of the Zorki (Зоркий) 35mm rangefinder cameras. Along with Fed, they were copies of the German Leica cameras. Zorki was an exact copy of the 1932 Leica II and was introduced in the market in 1948. It was made in several variations and was replaced by Zorki-2 in 1954, although it remained in production until 1956.
Zorki came with an Industar-22, 3.5/50mm lens, but other lenses were also available. The lens mount is the Leica's M39.
The film loads from the bottom and needs some practice to master. The film's leader needs to be trimmed, cut in half of its width for about 10cm (see video). This is a common practice for Leicas and similar bottom loading cameras because otherwise the film might damage the shutter curtains. Afterwards, you'll need to attach the leader to the take-up spool and only then insert both spool and film cassette inside the camera, at the same time, carefully.
Zorki is a good camera and a -much- cheaper alternative to the classical Leica. The camera is well made, though it might feel stiff at times and there might be problems with film loading and advance. But the lens will give you nice results and sharp images. Definitely a nice and fun camera to use.
Important things to remember:
#1 Always advance the film before choosing a shutter speed. Doing otherwise might damage the shutter and disorganize the speeds.
#2 Never attempt to turn the shutter speed dial between "Ζ" and "500" or you will damage it. You'll need to go all the way around.