This is an attempt to modernize the "Zenit-EM". The main improvement was new, easy to use speed dial, same as on Zenit 11 and Zenit 12.
Camera was prodused on new automatic assembly line and mostly intended for sale inside the USSR.
Zenit ET were produced in 2 major variation:
With Zenit EM type automatic aperture control, and was supplied with Helios 44M or Helios 44M-4 lenses.
Without automatic aperture control, Zenit E type and was supplied with Helios 44-2 or Industar 50-2 lenses.
Cameras with automatic aperture control are easy to spot by mushroom shatter release button, while manual aperture camera has smaller, straight release button.
In late 80-th to cut cost (and possibly to show development movements) many metal parts on Zenit ET was substituted by plastic (see Zenit ET - black and Zenit ET - bronze in Wiki)
Serial number was also moved from back of the camera and stamped inside of the back door.
Produced: 1981-1990 Chrome version and up to 1993 plastic versions.
Producer: Vileisk plant "Zenit" (BeLomo corporation), near capital of Belorussia - Minsk
Frame size: 24x36.
Industar 50-2 3.5/50.
Shutter speeds: 1/30s-1/500s + B.
Quantity: ±3.000.000 units (BeLomo)
Price in the middle of 80-th:
135 roubles with Helios 44M-4 or Helios 44M
100 roubles with Helios 44-2
77 roubles with Industar 50-2
(all prices taken from original 1987 manuals).