Differences Between Tank Solo And Tank Must

Since its launch in 1917, the Cartier Tank collection has become an iconic symbol in the watch industry, thanks to its highly recognizable rectangular case and design language inspired by military tank tracks. Among its lineup, the Tank Solo and Tank Must are often confused due to their similar positioning at first glance.

However, upon closer inspection, the Must—as a subsequent upgraded model—features comprehensive improvements in size, design, movement, and other aspects.
Today, we will break down these differences in detail

Differences of watch case Between Tank Solo And Tank Must
I. Tank Must vs. Tank Solo: Comprehensive Upgrades from Size to Details
The Tank Solo was once the “entry-level classic” of the Cartier Tank collection, winning popularity with its minimalist design.And Tank Solo has undergone a comprehensive upgrade based on its foundation.
I. Tank Must vs. Tank Solo
1:Watch Size
Both models offer 3 size options, but the Must features a more compact case (in terms of length and width) under the same size designation—especially the Small size, which is significantly more delicate. This makes it ideal for users with slender wrists or those who prefer a “small and exquisite” style. The specific size comparison (length × width) is as follows:

Small (Size S): Tank Solo measures 31mm×24.4mm, while the Tank Must is reduced to 29.5mm×22mm. The dial area is decreased by approximately 15%, ensuring a more snug fit on the wrist without a “wrist-heavy” feeling.
Large (Size L): Tank Solo is 34.8mm×27.4mm, and the Tank Must is 33.7mm×25.5mm. Despite the slight size adjustment, the Must appears slimmer visually and is suitable for both men and women.
Extra-Large (Size XL): The two models have similar dimensions (Tank Solo: 40.9mm×31mm; Tank Must: 41mm×31mm). However, due to the Must’s curved case design, it feels lighter when worn.
Difference Between Cartier Tank Solo And Tank Must (8)
Watch Size Guide For Cartier Tank Must & Tank Solo

*For reference only
Here are key tips for ladies choosing Cartier Tank and Tank Solo watches: Select the small case if your wrist circumference is between 14 cm and 16 cm, while the large case works better for wrists over 16 cm. Besides, the XL size is seldom favoread by female customers in most scenarios.
BTW, the watch case of small new Tank must is smaller than the small Tank Solo.
Different Lug Size Between Tank Must VS Tank Solo
Tnak Must Size Watch Case Represent Ref.
Small 16mm 29.9*22mm WSTA0042
Large 19mm 33.7*22.5mm WSTA0041
XL 23mm 41*31mm WSTA0040
Tnak Solo Size Size
Small 17mm 31*24mm W5200005
Large 20mm 34.8*27mm WSTA0028
XL 23mm 40.85*31mm WSTA0029
2. Dial Design: Closer to Historical Prototypes, More Elegant Details
The Must returns to the classic roots of the Tank collection, drawing inspiration from the Tank Louis . This gives it a more vintage overall style, creating a clear contrast with the “simple and straightforward” aesthetic of the Solo:

Lugs and Case: The Tank Solo has relatively sharp lug lines and a flat case design. In contrast, the Must’s lugs feature a “full and rounded curved finish,” transitioning more naturally with the case. Additionally, the Must’s case adopts a “curved structure,” which reflects soft metallic luster under light and looks more refined visually.
Dial Craftsmanship: The Tank Solo’s dial is mostly a solid-color flat design, with relatively simple texture. The Must, however, offers differentiated designs by size: Size S and L use “silvered dials,” which have a warm luster like silverware and pair with black Roman numerals for enhanced elegance; Size XL is upgraded to a “guilloché dial with hobnail pattern,” featuring delicate spiral textures on the dial surface. These textures are created through hand engraving, delivering a more layered look and touch than ordinary dials.
Crown Details: Both models have a spinel-set crown, but the Must’s spinel features a “slimmer and more elongated cut,” creating a visual contrast with the rounded lugs for a more balanced overall proportion. Additionally, the crown of the Must has deeper grooves, providing a clearer tactile feedback when adjusting.
Differences Between Tank Solo And Tank Must
Differences Between Tank Solo And Tank Must
3. Wearing Experience: Upgraded Buckle and Movement for Enhanced Practicality
Buckle Upgrade: The Tank Solo uses a traditional deployment clasp, which is secure but requires removing links to adjust the strap length. The Must switches to a “pin buckle design,” which is lighter in weight and allows flexible tightness adjustment through multiple holes on the strap. This is particularly convenient for users whose wrist size changes with temperature
Differences Between Tank Solo And Tank Must
Strap System: The Must’s strap interface features a “miniaturized design,” connecting more tightly with the lugs to prevent the strap from wobbling during wear. Additionally, some models support a “quick-release mechanism” (when paired with a compatible strap), allowing strap replacement without tools—more convenient than the Solo’s fixed interface.
Movement Battery Life: The Size S and L versions of the Must replace the Solo’s standard quartz movement with a “high-efficiency long-lasting quartz movement,” offering a battery life of up to 8 years. The Size XL version retains an automatic mechanical movement, preserving the enjoyment of owning a mechanical watch.
Quick Comparison Table
Feature Tank Solo Tank Must
Collection status Previous generation Current collection
Case shape Rectangular Rectangular
Small lug width 17mm 16mm
Large lug width 20mm 19mm
XL lug width 23mm 23mm
Case design More angular More curved
Dial style Simple design More varied designs
Strap options Leather / bracelet Leather / bracelet
Quick-release Reference dependent Reference dependent
Best for Classic Tank look Newer Tank design
II. Tank Must vs. Tank Louis Cartier
Many people confuse the Must with the Louis Cartier, but their positioning is distinctly different: the Louis Cartier is a “classic reissue model” focusing on “authentic historical charm,” while the Must is a “classic derivative model” emphasizing “balance between vintage style and practicality.” The specific differences are as follows:
Comparison Dimension Tank Must Tank Louis Cartier
Design Purpose Adapting the classic Tank design to modern daily wear Replicating the original 1920s design to restore historical charm
Case Material Mainly stainless steel, with some models featuring gold plating Mostly precious metals such as 18K gold and platinum
Dial Details Printed/metal applied hour markers, simple and clear Handcrafted enamel inlays for hour markers, more luxurious texture
Price Positioning Entry-level (approximately RMB 20,000-40,000), higher cost-effectiveness High-end collector-level (starting from approximately RMB 100,000)
Suitable Scenarios Daily commuting, casual matching Formal occasions, watch collection

Cartier Tank WSTA0041

Material: Stainless steel
Dimensions: 33.7mm × 25.5mm
Crown: Set with a synthetic cabochon spinel
Dial:Silvered opaline dial, paired with black Roman numeral hour markers
Clasp: Stainless steel pin buckle

Material:Calfskin Strap For Cartier
Seamless Fit: for Cartier.
Multiple Colors: black | grass green | chartreuse | white | pink | blue| lake blue and more
Comfortable Itlian Calfskin Leather
Flat End Calfskin Leather Watch Strap For Cartier Tank Solo Watch Band
IV. Recommendation of Steel Straps: Cartier Tank Must Bracelet and Cartier Tank Solo Bracelet
For models like the Tank Must and Solo, we offer “quick-release stainless steel straps” to solve the problems of limited original strap options and difficult replacement.

Precise Fit: Interfaces are according to the lug width of different Cartier moadels. No lug grinding is required during installation—just attach the strap directly to achieve a fit consistent with the original, with no looseness or wobbling.
High-Quality Material: Made of 316L medical-grade stainless steel,does not rust easily when exposed to sweat or rain in daily use. The surface undergoes “vacuum ion plating,” with color options (silver, rose gold, yellow gold) that perfectly match the color of Cartier cases and resist fading even with long-term wear.
User-Friendly Design: The links feature a “push-button quick-release structure,” allowing length adjustment without tools—easy even for beginners to operate.
Consistent Style: The strap design inherits Cartier’s “simple and elegant” style, with the link width gradually changing to match the lugs. Visually, it integrates seamlessly with the case, without disrupting the classic proportions of the Tank collection—maintaining the watch’s high-end texture even after replacement.
High End Steel Bracelet For Cartier Tank Must Tank Solo Men's & Women's 16mm 17.5mm 19mm 20mm 22mm 23mm
The Tank Solo has now been officially discontinued, and its “entry-level classic” position has been succeeded by the Tank Must. Compared to the Solo, the Must is closer to the historical essence of the Tank collection in design and better meets the needs of modern life in practicality。 It has become the “first choice for entry-level models” for users who love the Cartier Tank collection. If you are an owner of the old Solo model, you can also refresh your old watch by replacing it with our cartier tank must bracelet.

Cartier Stainless Steel Strap For Sale - Replacement Metal Watchband Fit For Cartier Tank Must New Quick Release (4)
New Quick Release Stainless Steel Bracelet For Cartier Tank Must
Stainless Steel Bracelet For Cartier Tank Must Solo 16mm 17.5mm 19mm 22mm Replacement Metal Watchband Fit For Cartier Tank For Sale (3)
Replacement Stainless Steel Bracelet For Cartier Tank Solo Tank Must (Mirror Polished With Matte Accent)
Video:Steel Bracelet For Cartier Tank Must Tank Solo

Video:How to clean metal watch strap

What Strap Size Does My Tank Need?
The correct replacement strap size depends on the exact Tank Must reference. Lug width is measured between the inside edges of the two lugs.

If you are not sure which strap fits your Cartier watch, our Cartier Replacement Straps Guide explains the different strap types, sizes and compatibility considerations for Cartier models.

Tank Must Lug Width
Small 16mm
Large 19mm
XL 23mm
Tank Solo Lug Width
Small 17mm
Large 20mm
XL 23mm
VI. FAQ
Q:Can the old Solo model be fitted with the new quick-release stainless steel strap?

A:Yes, but you first need to confirm the “lug width” of the old Solo model (i.e., the distance between the two lugs on the case)

Q:You offer custom straps for what cartier models?

A:Currently, we provide custom straps for multiple popular Cartier collections, including but not limited to:

Tank Collection: Tank Must (all sizes), Tank Solo (all sizes), Tank Louis Cartier, Tank Française;
Ballon Bleu de Cartier Collection: All sizes (33mm, 36mm, 42mm, etc.);
Santos de Cartier Collection: Medium, Large, and XL sizes;
Pasha de Cartier Collection: 35mm and 41mm;
Other Collections: Ballon Blanc de Cartier, Ronde Louis Cartier, etc.
Custom straps are made with molds tailored to the lug shape and interface structure of each specific model, ensuring a 100% fit.

Q:What types of Cartier watch straps do you offer?

Rubber Velcro Strap: Made of fluororubber, it is waterproof, sweat-resistant, and anti-aging—suitable for summer wear or sports scenarios. The Velcro design allows free adjustment of tightness to fit various wrist sizes. Color options include black, blue, red, etc., making it ideal for pairing with sports-style watches.
Leather Strap: Materials include Italian full-grain cowhide, crocodile leather (Siamese crocodile, American alligator), and ostrich leather. Cowhide straps are durable and easy to maintain, suitable for daily commuting. Crocodile leather straps are hand-stitched with edge sealing, offering a luxurious texture for formal occasions. Color options include classic shades such as black, brown, and burgundy, which can match different case colors.
Stainless Steel Strap: In addition to the quick-release stainless steel strap recommended above, we also offer styles like “five-link straps” and “Milanese mesh straps.” All are made of 316L stainless steel, with some high-end models using 904L steel. Surface treatments include brushing, polishing, and sandblasting—you can choose according to the watch style. They are suitable for year-round wear and easy to clean and maintain.
Q: Are all the links made of solid steel?

A:Yes, every single link of this band is fully machined from solid 316L stainless steel, no hollow thin steel links.

Q: Is Tank Must smaller than Tank Solo?

A: In several comparable sizes, the Tank Must has a slightly smaller case than the Tank Solo. For example, the Tank Must Small (Ref. WSTA0042) measures 29.5 × 22 mm with a 16 mm lug width, while the Tank Solo Small is approximately 31 × 24.4 mm with a 17 mm lug width. However, case dimensions vary by reference, so check the exact model before choosing a replacement strap.

Q: Can Tank Solo use a stainless steel bracelet?

A: Yes, a Tank Solo can be fitted with a stainless steel bracelet when the bracelet is specifically designed for the watch’s case and lug dimensions. Because Tank Solo models use different lug widths depending on size, you should confirm your exact reference before ordering. A properly fitted replacement bracelet should match the case without forcing or modifying the lugs.

Q: Is Cartier Tank Solo discontinued?
A: Yes. The Cartier Tank Solo has been discontinued and replaced in Cartier’s current entry-level Tank lineup by the Tank Must. Cartier’s current collection lists Tank Must models in Small, Large and Extra-Large sizes, while Tank Solo is no longer part of the current collection.

Read More Differences Between Tank Solo And Tank Must