Seiko Premier SSA399J1 is more than just an open heart dial design.
Movement: Automatic with manual windingCaliber 4R71; Jewels: 24
Power reserve: 41 hours
Case: Stainless steel 42.9 mm x 12 mm
Dial: textured skeletonized blue with open heart
Crystal: Scratch resistant Sapphire
Water resistance: 100 m
See-through screw case back
Blue leather strap with three-fold clasp & push button release
Stop second hand function
Made in Japan