The manual-winding Caliber 9SA4, like its automatic counterpart, boasts an impressive 80-hour power reserve, thanks to its efficient Dual Impulse Escapement and twin barrels. Featuring Grand Seiko's Free-sprung Balance and a hairspring with overcoil, it ensures stability, resistance to external influences, and superior performance. Caliber 9SA4 undergoes rigorous testing in six positions at three temperatures over a 17-day period to meet Grand Seiko's high standards. While sharing similarities with Caliber 9SA5, the redesigned Caliber 9SA4 sees nearly 40 percent of its base movement reconstructed to enhance the tactile winding experience. Notably, the movement’s click, essential for preventing the mainspring from unwinding, has been refined for optimal feel and sound. The crown halts when the movement reaches full power, with the click shaped like a wagtail, a bird symbolic of Morioka, the city near the Grand Seiko Studio Shizukuishi where all Grand Seiko mechanical watches are meticulously crafted.

Accompanying the debut of Caliber 9SA4 is a new dress watch design from the Evolution 9 Collection, continuing Grand Seiko’s iconic lineage traced back to the legendary 44GS from 1967. This refined Evolution 9 Style embodies the charm, elegance, grace, and subtlety expected of a hand-wound dress watch, with features such as slimmed-down and elongated grooved indexes and narrowed multifaceted lugs for enhanced aesthetic appeal. The SLGW003 features a case crafted from Brilliant Hard Titanium, and a new dial pattern inspired by the intricate texture of the birch tree's bark.  

Grand Seiko's newest mechanical timepieces boast a sleeker profile with a diameter of 38.6mm and a thickness of just 9.95mm, ensuring both comfort and stability. The lowered center of gravity aligns with the esteemed standards of Grand Seiko’s Evolution 9 creations.