Swiss Sellita SW215-1 Manual Winding Movement
Because pilots, conductors, streetcar, subway drivers Have To Be On Time. Seconds count to a bomber, minutes count on runways, accurate departure and arrival times are essential at airports and stations everywhere.
The phrase "Be On The Ball!" was coined because of the Ball Watch Company. This American watch company was so accurate that seemingly all conductors trusted their pocket watches and watches.
The phrase means be there to the second, to the minute. It has evolved to mean "be at the top of your game". To be "alert", aware, and "ready to take action". American Precision is why that phrase is coined.
The Precision of this movement is to within seconds a day. The Cincinnati Watch Company tests every one of our movement's accuracy and Precision. If a movement is outside of the Swiss factory tolerances we micro adjust the movement to within expected specifications provided by the Swiss producers of the Sellita (Swiss) SW215-1 Manual winding movement.
The SW215-1 has proven to be not only within the tolerances of the provided standards, the movement is proven to be very very accurate. Many were below +-1-3 seconds per day. Most were +-3-7, some were +-8-12 seconds per day. An incredibly accurate mechanical watch movement
*Image Credit http://calibercorner.com/sellita-caliber-sw215-1/