When Soviet designers started to work on the ZSh-5 series of helmets, the need for a new oxygen mask arose. Initially, It was probably decided to upgrade the KM-32 design to be able to connect to the ZSh-5, but as the work on the mask started, a few improvements were also made to the old design.

First step was to upgrade the mask hooks. Old style hooks used on KM-16/KM-32 mask and over-the-head straps designs proved to be rather uncomfortable and Russians introduced a new hooks design which is still used on modern KM-35 masks. New hooks are made out of a metal strip inside of which 2 S-like metal rods are inserted. The outside ends have plastic caps which act as buttons, inside ends have small "arrows" that point outside of the metal strip and act as anchors inside of the helmet's mask receivers. Rods are spring loaded so that after being squeezed they would automatically return in their original position and allow anchors to lock inside of the mask receivers.

Secondly, mask size was increased which made it more comfortable to wear. The rubber mask was also given an outside fiberglass shell which made it more sturdy and probably safer for the pilot to wear. The oxygen hose attachment point was relocated to the front of the mask, but the inhale valve itself stayed on the right side of the mask (just like in KM-32). To supply it with air, rubber piece had a channel inside which connected the valve to the hose. Pressure valve stayed unchanged and was also located in the front, right above the oxygen hose. The left side of the mask has a round bump into which internal microphone could be placed (though most of the time pilots still used old laringophones and internal microphone became more or less standard only in late production models of KM-34Ds and became standard on KM-34D series 2 and KM-35 masks). Also located on the left side was the attachment point for the occipital bladder.

After all of the changes and improvements mask became known as the KM-34.

 

KM-32's big brother - KM-34. Thanks to its new outer fiberglass shell, this new design looks little like its predecessor, but a look inside will show that nothing really changed.
KM-34 has 2 stams located near the oxygen hose attachment point. The one on the right bears the name of the mask - KM-34...
... The left stamp which tells us the size of the mask, in this case size 3.
New hook design made it easier and more comfortable to attach new mask to the helmet.
Inside, KM-34 is nothing more then the old KM-32 oxygen mask. Shown on this picture is the right side of the mask. In the front is the inside part of the pressure valve. On the right is the oxygen flow valve covered by a thin round piece of rubber - it prevents foreign objects and moisture from getting inside of the valve.
Left side of the mask. In the front is once again the pressure valve. To the left is the round opening into which internal microphone could be placed (when mask is used without the built in microphone, buttom part of the opening is covered by a rubber piece to help keep constant pressure inside of the mask). Between the pressure valve and the opening for the microphone is a small round metal plug with an opening in the middle - this is the inside part of a small rubber hose used to connect occipital bladder to the mask.
This is how the microphone bump looks on the outer side of the rubber mask. In the best KM-32 tradition, the top line gives the name of the mask, middle line is the size and the bottom are the two last digits of the year when it was produced. This mask was made in 1979, one of the last original KM-34 masks produced... Worth noting here is that this information relates only to the rubber part of the mask, fiberglass shell has its own markings.
Fiberglass shell has two ID tags attached to it on the inside. The first one gives us name of the mask, size and its ID number...
... Second ID tag says "OTK II-79", which most likely refers to the date of production of the fiberglass shell.
To round up this page, here is a picture that shows possible fighter pilot setup of the late 1960s- 1970s - it consist of the early ZSh-5 helmet (in this case with blue visor, but any ZSh-5 could do), KM-34 oxygen mask and LA-5 laringophone.
Here is another example of the original KM-34 design. This one is rather interesting because its shell is made out of non-standard white colored fiberglass. The reason behind this is unknown. In US, white colored flight gear was used to lessen the effect of a nuclear flash, so it is possible Russians did the same thing, or it could be just a simple color switch which occured on a small production batch.
Another look at the white shell. It is definately made out of white colored fiberglass. It was not repainted, nor it is a much faded usual green color.
Here is the production tag located inside of the fiberglass shell. Shell was made in April 1978.
ID tag which shows the model, size and serial number of the mask.
Rubber piece was also produced in 1978...