After the KM-16 it seems as Soviet designers concentrated on copying American oxygen masks and it was not until the KM-30 that they produced their own design. KM-30 was a major step forward from the KM-16 and arguably in many respects was better then US designs of that time. It was a big mask capable of providing much more oxygen to the pilot then the KM-16. KM-30 was also the first oxygen mask that was equiped with an occipital bladder - a major advantage over US masks which only recently started to be manufactured with similar bladders.

Unlike KM-16, KM-30 required helmets equipped with special hooks. This helmet is in fact a modified ShL-50 with two horizontal straps with hooks on each of their ends (a total of 4 hooks). Since ShL-50 did not have a provision for occiptal bladder inside of it, bladder was equipped with straps that would allow it to be attached to the helmet's back from outside.

KM-30M is extremely hard to find and will be a nice addition to any Soviet collection.

 

KM-30M mask from inside.
KM-30 occipital bladder. Note the straps via which it attaches to the helmet.
KM-30M attached to specially modified ShL-50 helmet.
Right view - note how the mask and its occipital bladder are attached to the helmet.
Yet another shot of the KM-30M mask. Note how far down it covers pilot's face.
Pilot combination that consists of the special ShL-50 helmet, KM-30M mask and PO-1M goggles. Check page 1 of the "In Action" section for a picture of Soviet pilot wearing similar combo.
Left view - this setup looks more bulkier then the rest of leather helmet combinations.