The Jaeger - LeCoultre [ref 161.64.2A (Q161642A)]watch have mechanical Movement with a 8 Day PowerReserve. This watch greatly features Perpetual Calendar which will automatically compute the day, date, month, year & phase of the moon correctly until March 1st 2100 & mandates a correction only once every 122 years. Day denoted by the sub-dial at the 9 o'clock position. Date designated by the sub-dial at the 3 o'clock position. Month gestured by the sub-dial at the 6 o'clock position. Year window displayed between the 7 & 8 o'clock position. Jaeger - LeCoultre [ref 161.64.2A (Q161642A)]watch shows Moon-Phase at the center of the day sub-dial at the 9 o'clock position.also shows Power Reserve located at the 11 o'clock position. Day/Night (AM/PM) indicator located at the 11 o'clock position. Transparent case back - movement stunningly finished with beautiful Coates Soleillees (sunburst finish). This watchis perfect and you will need no more style and usessince it has all the needs.