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The official 2025 blue-sapphire model is the Hublot Big Bang Unico Water Blue Sapphire, reference 421.JL.4890.RT. Hublot lists a 44 mm sapphire case, its HUB1280 flyback chronograph movement and a 50-piece limited edition. This is a specifications-led review, not a first-person wear test: comfort, legibility, weight and durability have not been independently assessed here.
Which Hublot Blue Sapphire is this?
“Big Bang Unico Blue Sapphire” can refer to more than one watch. Hublot’s April 1, 2025 release identifies the blue model as the Big Bang Unico Water Blue Sapphire, reference 421.JL.4890.RT. Its 44 mm case and bezel are Water Blue sapphire crystal. The reference matters: the current clear 42 mm Big Bang Unico Sapphire and the original 2016 clear 45 mm model are different watches, not alternate descriptions of this blue edition.
| Model | Reference and date | Case and movement | Edition and distinction |
|---|---|---|---|
| Big Bang Unico Water Blue Sapphire | 421.JL.4890.RT; 2025 | 44 mm; HUB1280 flyback chronograph | 50 pieces; Water Blue sapphire case and bezel |
| Big Bang Unico Sapphire 42 mm | 441.JX.4802.RT; current US listing | 42 mm; HUB1280 flyback chronograph | 500 pieces; clear Sapphire listing, not the Water Blue reference |
| Original clear Big Bang Unico Sapphire | 2016 launch reporting | 45 mm; HUB1242 flyback chronograph | 500 pieces; Hodinkee reported a $57,900 launch price |
Sources: Hublot’s current US 42 mm listing, Hublot’s 2025 Water Blue release, and Hodinkee’s 2016 launch report. The historical price applies only to the original clear model at launch.
What are the Water Blue Sapphire’s specifications?
These are Hublot’s published specifications, not independent measurements:
#1 Best Overall
- Made of non-allergic natural resin, waterproof, soft, light, durable, comfortable to wear
- It is suitable for Hublot Big Bang 25 * 19 * 22mm interface watch band , not for other watches
- It is very important to choose the correct model. To avoid the trouble caused by the return and exchange of goods, if you have any questions about the model and size of the watch, please feel free to contact us
- Package included: 1 * Rubber strap (without metal buckle), 1 * tool kit, easy replacement with our free tools. The watch has a new look! It is not the original and is a good substitute
- Case: 44 mm, polished Water Blue sapphire crystal case and bezel.
- Dial: transparent skeleton dial, with blue accents on the indexes and hands.
- Movement: HUB1280 UNICO self-winding flyback chronograph with column wheel. Hublot describes it as built from 354 components.
- Power reserve: approximately 72 hours, as stated by Hublot.
- Water resistance: 50 m / 5 ATM according to Hublot. This is a stated rating, not an endorsement for diving.
- Strap and clasp: transparent Water Blue lined rubber strap and titanium deployant buckle.
- Edition: limited to 50 pieces according to Hublot.
Hublot summarizes the color treatment this way: “Measuring 44mm wide, the case and bezel are matched by the translucent blue rubber strap, as well as the blue accents on open dial’s indexes and hands.” The statement is from Hublot’s release dated April 1, 2025.
What makes the sapphire construction distinctive?
The central design idea is a colored transparent case that leaves the skeletonized movement visible. Hublot says its engineers and chemists developed transparent material to reveal the watch’s mechanism while protecting it. That is the manufacturer’s description; the cited specifications do not establish independent scratch or impact-test results. Sapphire construction alone should not be treated as proof of how this particular watch performs after a knock or in daily wear.
Rank #2
- Compatible Watch Models: Perfect Compatible with Hublot Big Bang 19mm×25mm×22mm Series Watches,
- Product Include: 1× replacement watch band with mental buckle+ 1× strap removal tool+ 1×screwdrivers+ 2× Spring Bar+strap outer packaging. Using the included replacement tool, you can quickly install the strap.
- Select The Appropriate Width: Compatible with Hublot Big Bang size (19mm×25mm×22mm) straps, Measure the size near the strap buckle or the inside of the strap.
- High Quality Materials: High quality Leather material, waterproof and sweatproof, dust-free. Compatible with Hublot Big Bang size (19mm×25mm×22mm) straps.
- Have any questions on how to choose the size, please contact customer service
How does the chronograph work?
Hublot specifies the HUB1280 UNICO, an automatic flyback chronograph with a column wheel. A flyback chronograph is designed to let the wearer reset and restart timing in one action, rather than stopping, resetting and restarting separately. The column wheel is a movement-control component associated with chronograph operation. The published information establishes the mechanism and stated functions, but does not supply independent timing or operating tests.
How large will it wear, and is it legible?
The official case diameter is 44 mm. Diameter is only one part of fit: wrist comfort also depends on case shape, thickness, lug geometry, strap fit and the wearer’s wrist. The available specifications do not establish those on-wrist impressions, nor do they establish how easily the open dial can be read under different lighting or at a glance. Anyone considering the watch should try the exact reference in person if possible rather than infer comfort or legibility from photographs.
Rank #3
- Compatible Models: 44.5mm Hublot Big Bang Luna Rossa 301.CM.131.RX.LUN06 , 301-CM-131-RX-LUN06, 301/CM/131/RX/LUN06, 301CM131RXLUN06 watches which has 25mm at lugs and 22mm at the buckle
- Detailed Sizes: Lug Size: 25mm; Lug Smaller Size: 19mm; Width at Buckle: 22mm; Length: 100/80mm
- High-quality rubber and stainless steel watch band & clasp.
- Package Including: 1 set (2 rubber strap) And 1 Clasp
- Your Satisfaction Is Our Highest Priority. Pls Contact Us If You Have Any Questions, We Will Try Our Best To Serve For You.
How scarce is it, and where can you buy it?
Hublot says the Water Blue edition is limited to 50 pieces and identifies its boutiques and authorized retailers as availability channels. A stated edition size does not establish current stock. The available information does not establish a current Water Blue price or local availability. Ask a Hublot boutique or authorized retailer to confirm the exact reference, local price, stock, warranty terms and authenticity before purchase. Do not use the $57,900 figure reported for the 2016 clear model as a price for the 2025 Water Blue.
Quick Recap
Best Value
- Using high quality Nature Rubber materials. Make you feel light, strong, soft and flexible in the process of wearing.
- Compatible with Hublot 25mm Band: Replacement for 25 mm Big Bang Series watch band
- Band Width: 25mm.
- WHAT YOU GET: 1 x Rubber Watch Band, 1 x Spring Bar Tool, 2 x Strap Pins.
- If you have any problems, please feel free to contact with us. We are very happy to help you.
Rank #4
- -It will fit the Hublot Big Bang watch which has 24mm/25mm lugs；Replacement 24mm/25mm RUBBER BAND STRAP for 44-45 H Fusion
- -Made to fit Big Bang 44mm, 44.5mm & 45mm watches which has 24mm/25mm at lugs and 22mm at the buckle and it fits perfectly
- -This Strap is made of Highest Quality Silicone Rubber
- Lug Size: 24mm/25mm，Multiple sizes Lug Smaller Size: 17.5mm/19mm. Multiple sizes Width at Buckle: 22mm Made for 12-24-80 clasp end and 12-25-100 long size Screw Hole Distance: 12.5mm
- We sell only the best quality replacement watch parts and accessories for the watch. We have been selling online for over 10 years. If you have any questions, please contact us in time.100% Satisfaction Guarantee!
What to verify before buying
- Confirm the reference: check that the watch and sales documents identify 421.JL.4890.RT, not the 42 mm clear reference 441.JX.4802.RT or the older 45 mm model.
- Check the physical configuration: verify the Water Blue sapphire case and bezel, transparent Water Blue lined rubber strap and titanium deployant buckle against the listing.
- Get current terms from the seller: confirm local price, actual availability, warranty coverage and the seller’s authorized status directly.
- Assess fit and dial readability yourself: try the watch on in person where possible; published dimensions and images cannot settle those questions.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
