Crafting watches since 2007
Designed in Stockholm, Sweden
Warranty on all watches
+1,500,000 Watches Sold
Crafting watches since 2007
Warranty on all watches
Designed in Stockholm, Sweden
+1,500,000 Watches Sold
A guide for the

Koster Watch

As a GMT watch, Koster runs one additional hand and thus more mechanisms, resulting in more settings that are adjusted via the crown. Read through this compact manual before using the watch.

1. WATER RESISTANCE

This watch uses a screw-down crown, which must be fully tightened onto the case when worn. This ensures the 20 ATM water resistance; if the crown is unscrewed, keep the watch away from water.

To Close the Crown:

  1. Remove the time stopper (the small plastic piece sitting between the crown and thread on new watches).

  2. Gently push the crown toward the case until you feel it set or "sink" slightly.

  3. While maintaining light pressure, screw the crown clockwise until it tightens onto the threads.

  4. Screw the crown until you cannot screw it anymore. Do not use excessive force when tightening.

2. DATE CHANGING PHASE

Do not perform date corrections while the watch is displaying time between 9:00 PM and 3:00 AM.

This is because the watch movement is actively engaging the gear system to change the date during this window. Adjusting the date during this time can severely damage the movement.

3. USING THE CROWN

Always turn the crown gently and smoothly when performing any corrections/changes. Never use excessive force.

4. CHANGING TIME

  1. Unscrew the crown counterclockwise until it releases from the threads.

  2. Gently pull out the crown until you feel two consecutive clicks, this is the time changing setting.

  3. Carefully turn the crown clockwise/counterclockwise until the hands display the correct time.

5. CHANGING DATE

  1. Unscrew the crown counterclockwise until it releases from the threads.

  2. Pull the crown out gently to the first click (Position 1).

  3. Carefully spin the crown clockwise until the date window displays the correct date.

IMPORTANT: See the “Date changing phase” section above before performing a date change.

6. CHANGING GMT TIME

  1. Unscrew the crown counterclockwise until it releases from the threads.

  2. Pull the crown out gently to the first click (Position 1).

  3. Carefully turn the crown counterclockwise until the GMT hand displays the correct time.

Now you are in tune with how to operate the watch. We hope you bring it with you on many adventures to come! Best Wishes, TRIWA Team