Grand Seiko Sport Collection 9F Quartz GMT 39mm Watch alt text ai The screw back case is topped &Co The screw back case is topped with a mineral crystal exhibition window to showcase the automatic movement powering the timepiece 4 mm stainless steel casebody and is presented on a stainless steel and 18K yellow gold bracelet Calibre 9F was developed to allow the creation of the ultimate quartz watch and is now widely recognized as one of the finest quartz calibres in the world The high precision (+ 10 seconds a year) of Caliber 9F86 is not compromised when the time zone is changed as the watch continues to keep perfect time even when the crown is pulled out and the hour hand is moved to adjust the local time