The Grand Seiko SBGY007 Omiwatari: case, stainless steel, 38.5mm x 10.2mm; 30 meters water resistance. Movement, hand-wound Spring Drive caliber 9r31, rated to ±1 second https://www.rbsunglasses.uk.com/product-sunglasses/erika-classic-exclusive/ per day maximum deviation in rate; power reserve https://www.rbsonnenbrillen.de/sonnenbrillen/new-wayfarer-classic/ 72 hours, running in 30 jewels. Available this July. Find out more at Grand-Seiko .Thanks to Mr. Jeff Lessard, who pointed out by email that the 9R31 was also used in a https://www.rbsunglasses.uk.com/product-sunglasses/aviator-max/ 22-piece limited edition for Japan, SBGY005.