The first Grand Quartz was released in 1975 boasting a monthly accuracy of ±5 seconds. This was followed by the Grand Twin Quartz using the 9943 calibre, an ultra-high precision movement with an annual variation of only ±10 seconds. The double quartz oscillation mark (also known amongst collectors as the “double dick” logo) at the 6 o’clock position indicates that this is a twin quartz movement.

Photo : GrandSeiko