New
Nautilus Open Heart Mod Style | Black Sunburst Dial 40mm | Seiko Mod
$250.00
✓ Shipping & Delivery
Not available
Not available
✓ Estimated Delivery
September 11, 2025
September 11, 2025
Description
The Seiko Nautilus Open Heart Mod (aka Seikonaut) combines the iconic Nautilus design with the precision of Seiko’s NH38 automatic movement. Featuring a 40mm stainless steel case, sapphire crystal, and a black sunburst dial with open-heart display, this timepiece merges elegance with technical craftsmanship. With luminous indices, an exhibition case back, and an integrated steel bracelet, this hand-assembled masterpiece is a standout in any collection.
Features
Case Material
316L Stainless Steel
Dial Black Sunburst, Open Heart Window
Crystal Sapphire (front & back)
Case Back Exhibition Sapphire
Crown Screw-down
Optional Strap Natural rubber (sport variation)
Wrist Size 14.5cm – 22cm
Water Resistance 50m (5 ATM)
Technical Data
Diameter
40mm
Material
Solid 316L Stainless Steel
Power Reserve
41 hours
Accuracy
-20 ~ +40 sec/day
Jewels
24
Beat Rate
21,600 bph
Bracelet
Bracelet: Integrated 316L Steel, Butterfly clasp
30 people are viewing this right now

Guaranteed safe & secure checkout










Specialisations
Seiko NH38 Automatic (Open Heart)
About the brand
Questions
Nautilus
There are no question found.