A model inspired by the first domestically produced crystal glass model "Crystal Seven"that appeared in 1965. It is a wristwatch with a date and day calendar that is the thinnest in the world at that time and the day display is proudly arranged at 12 o'clock. / Caliber: 8200 / Static accuracy: Daily difference -20 to +40 seconds * / Mechanical wristwatch / Automatic winding + Manual winding / Frequency: 21600 times / hour / Number of stones: 21 stones / Date early correction function / Day of the week early correction Function / Japanese-English switching function / Drive time approx. 40 hours (at maximum hoisting) / / * Accuracy is measured in the static state of the movement. Due to the characteristics of the mechanical watch the daily difference range may be exceeded depending on the conditions of use (carrying time watch posture arm movement winding condition of the mainspring etc.). The drive time is a guide. / 5 ATM water resistant / luminous / see-through back