Square Nautilus-inspired 5821 Blue Sunburst Full Steel Super Clone

Premium top-tier factory exclusive launch: the all-new 2025 Square Nautilus-inspired 5821 large size model, the bold nautilus-inspired square sports timepiece that features the original official blue color, perfect for collectors who pursue the authentic classic experience. Many of our US customers also refer to this model as Cubitus 5821, that's why we know this is exactly what you are looking for.

This model is designed specifically for men with bigger wrists who love the original official color, following the legendary 5711, this is the bold large-size version that delivers the exact same authentic look as the official version, ideal for users who prefer the most classic, minimalist look than the smaller 40mm version. No more struggling to find the original official color version that fits your big wrist, we've got you covered.

Core Craftsmanship Highlights

• Upgraded Stop-seconds Movement: Equipped with the customized 9015 modified Cal.26-330 SC integrated automatic self-winding movement, exactly the same movement used in all our top-tier Square Nautilus-inspired watches. This upgraded movement features stop-seconds function when setting time, the balance wheel position matches the authentic version exactly. It delivers precise sweep seconds, 35-45 hours power reserve, and the exact same visual layout as the official version, no details are missed, perfect for daily wear, you don't have to worry about time accuracy at all.
• Authentic 316L Steel Bracelet with New Clasp: Equipped with 316L medical-grade custom ergonomic steel bracelet, paired with the upgraded new fold-over clasp that you won't find in low-quality watch. The bracelet has the exact same satin-brushed and polished finish as the official version, and we provide free size adjustment for big wrists - even if you have a 9.5 inch extra large wrist, we can extend the bracelet to fit you perfectly, no extra charge. It provides all-day comfort without any irritation, while the new clasp ensures secure and easy wearing, just like the authentic version.
• Exact Official Size & Weight: With a 45mm case diagonal measurement (from 10 o'clock to 4 o'clock, excluding the crown), the case thickness is only 8.3mm, exactly the same as the official version. Many big wrist collectors worry that large watches are too heavy to wear all day, but this ultra-thin case delivers a premium solid feel without the weight, you can wear it for work, daily outings, or collection display without any pressure on your wrist.

The stunning authentic blue sunburst dial features a unique horizontally embossed pattern, catching light from every angle to create a subtle, changing visual effect - sometimes it shows a soft blue tone, sometimes it shows a calm gray tone, exactly the same as the original official color. This is the most classic original official color in the entire 5821 collection, it's the most minimalist and versatile style that can match any outfit perfectly. Many big wrist users who love the original color worry that they can't find a large size version that fits their wrist, but this model solves that problem perfectly, it brings you the exact authentic experience of the original official color, but in a large size that fits your big wrist. The contrast between vertical satin-brushed and polished finishes on the case and bracelet highlights the bold geometry of the large square case with rounded corners, making it perfect for any occasion, whether it's formal business meetings, casual daily wear, or weekend gatherings.

Our Premium Service Guarantee (Same as our entire collection)

• Video Proof Before Shipping: Just like all our Square Nautilus-inspired watches, we will take exclusive real video for you before shipping, you can check every detail of this authentic blue watch before payment, no scam, no fraud, you know exactly what you are getting.
• Discreet Worldwide Delivery: Plain packaging without any logo, customs-friendly shipping, full tracking available, deliver to your door safely.
• 2-Year Full Warranty: We provide 2-year full warranty for all our watches, any movement or craft problem, we will fix it for free, you don't have to worry about the quality.
• Free Bracelet Adjustment for Big Wrists: Exclusive free size adjustment service for big wrist users, we can extend the bracelet to fit up to 9.5 inches wrist perfectly, no extra charge.
• No Reason Return: 7 days no reason return policy, if you are not satisfied with your watch, you can return it for full refund.

If you like this 45mm big wrist basic style, you might also be interested in:

• Our 7128 Regular Wrist Basic Collection, if you have a regular wrist and want a smaller case size
• Our 5822 Big Wrist Annual Calendar Collection, if you want the multi-function annual calendar model for big wrists
• Our 5821 Full Pavé Diamond Collection, if you are looking for the luxury iced out style