Seiko Presage x Automatic ft. Cocktail Time aka Open Heart aka Blue Acapulco Men Formal Round 50m Water Resistant Watch SSA439J1 SSA439 SSA-439 SSA-439J1 Discover the Seiko Presage Cocktail Time SSA439 and SSA441, featuring stunning open-heart dials inspired by Japanese cocktails. These 40.5mm automatic watches house the Caliber 4R38 movement with 41-hour power reserves, box-shaped Hardlex crystals, and stylish stainless steel bracelets Caliber Number / Movement 4R38 (automatic with manual winding capacity) Power Reserve / Accuracy Approximately 41 hours (+40 to -20 seconds per day) Crystal Hardlex crystal (curved) Luminous Nil Case / Band Material Stainless steel case with stainless steel band (deployment clasp with push-button release) Water Resistance 50m / 5 bar Case Size Thickness: 11.8 mm Diameter: 40.5 mm Length: 47.5 mm Lug width: 20.0 mm Other Specifications Seiko Presage x Automatic ft. Cocktail Time aka Open Heart aka Blue Acapulco Made in Japan See-through case back Screw case back 24 jewels Stop second hand function (hacking mechanism) Regular timekeeping (analog display)