This 7806 reference of the famous Navitimer is a lot rarer than the 806. Instead of the regular Venus movement, this caliber uses the Valjoux 7740 with date function. This seldom-seen caliber (only used between 1972 and 1974) is a mechanical hand-wound movement. It counts 17 jewels and has a frequency of 28800 alt/h. The power reserve (observed) appears to be around 42 hours. The chronograph module (cam activated) used in this 7740 comes from the ChronoMatic cal.11 and 12. 

This Navitimer is in very good vintage condition and comes with full service! Including Breitling leather strap and buckle, Wooden Q Watches Box & GoldCard.