Company Vostok design is specialised in medals, cups, memorabilias. I don't know how this company got involved into production (or better say just reselling) of watches with the brand name Ratnik, which are watches for the russian military forces. Watches are powered by automatic Vostok movement, official producer of the watches is supossed to be "Moskovskij časovij zavod -MFČZ)", the company which is unknown to me. Watches are also available for the civil market however they are not always easily available since army buys watches in high numbers and army has priority.
One of the most important properties of domestic 6e4-2 watches is their ability to resist the effects of an electromagnetic pulse. The watch from the set of military equipment Ratnik has passed long-term tests for its ability to withstand the effects of high and low temperatures, moisture, harmful radiation, and mechanical shocks. The 6e4-2 watch can be operated at temperatures from minus 40 to plus 50 degrees, subject to being on the arm.