Rare, all original, excellent working condition. Complete with 3 rolls of tape and its original signed case. Great design, high quality aluminum and metal construction. Signed Favag Neuchatel Switzerland on both the instrument and case. Model type 175110.001/52, serial 1147 005. Battery operated, not included to avoid leaks during shipping. Measures 11 x 6 3/4 x 8 3/4 inches and weighs 16 pounds. This chronograph was used to measure and record on paper tape time intervals precise at 1/100 of a second. This chronograph, synchronized with time signal received from a shortwave radio, was used in conjunction with a chronometer and the eyepiece micrometer of a T4 astronomical theodolite (such as the Wild T4) in order to reproduce their time record in graphical form. It is known as a tape chronograph since it features two circular reels with continuous strips of paper, and the paper is fed through the instrument at a uniform rate. It incorporates a clock-driven mechanism which moves the strip of paper at a steady rate (about 1cm/sec). It has a small electrical motor and the speed is regulated by means of a rheostat. The records of micrometer contacts (from the theodolite) are made alongside that of the chronometer seconds, instead of being superimposed upon it. The device uses needles instead of pens and a series of fine punctures on the strip of paper forms the record (Information source: Worthopedia).