The movement in this watch is a Lemania cal. 1341, an automatic, three register, cam lever chronograph. What makes this calibre interesting, both technicaly and visually, is that the minute register for the chronograph is not presented in a subdial, but as a seperate minute hand that sweeps around the dial. The subdials in this calibre are an hour recorder at six, and running seconds at nince 'o clock. The cal. 1341 is a simplified version of the cal. 1340 which was first introduced in 1972. The main difference between the two is that the cal. 1341 has 17 rather than 22 jewels, and has no facility for adding a 24 hr function. Brand: Tissot Movement: Automatic Case material:Steel Bracelet material: Steel Year: 1975 Gender: Men's watch/Unisex Case material: Steel Case diameter: 39.5 mm Waterproof: Not Waterproof Glass: Plexiglass Dial: Black Bracelet material: Steel Clasp: Buckle orginal tissot Clasp material: Steel Functions: Chronograph, Date, Tachymeter Others: Center Seconds, Small Seconds, Luminescent Hands, Quick Set, Only Original Parts, Luminous indexes Please see the photo's. All original vintage navigator . NO Box and papers Registered and insured shipping