As its name says, the Zenit 412DX adds to previous models automatic entry of the film speed by reading the DX code of the cartridge; The 412ls gives an improvement of this feature: while the former only recognizes 100, 200 or 400 iso, the new model reads from 25 to 1600 ISO. There is no possibility of manual adjustment of the sensitivity; in case of non-coded cartridge (or unreadable) the meter is set to 100 iso.The 412 resembles the 312, but the molding of the shell is different.
Back opened to see the DX code reading contacts. The film drive shaft is made of white plastic.
The complete set: the camera, with lens cap, strap, carrying bag, manual and "certificate" (in Russian).