VERY RARE military aviation watch of the USSR daily 55m daily 24 hours work? The hour block is rare and produced in small quantities. The clock “block 55M” is intended for measuring the current time in hours and minutes and switching electrical circuits in accordance with a given time program in aviation technology. The clock was installed on one of the blocks of the identification system “6201” (friend or foe) and was intended to automatically switch the identification codes of an aircraft radar interrogator-responder. They have a built-in block of switches and, unlike conventional watches, a 24-hour dial to eliminate double operation per day. The scales and hands are covered with TEMPORARY! Phosphorus (has nothing to do with radioactivity), which has the effect of a residual glow in the dark after irradiation with ordinary light, or a bright glow in the dark under the influence of ultraviolet irradiation of ARUFOSH fittings used to illuminate aircraft cockpit instruments. The red arrow is intended to set the response time of the contact group. It also triggers automatically at 24:00. The “6201” system was installed on all aircraft and helicopters of the USSR (RF) Ministry of Defense. Most likely it still is. The device is produced by the Chelyabinsk Watch Factory. Electric contact winding with mechanical and electrical (27 volts DC) winding, which lasts up to a week of watch movement.