Differences Between Tank Solo And Tank Must

Author:Royalwatchstrap
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

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.

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

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.
4.Related Product
Replacement Stainless Steel Bracelet For Cartier Tank Solo Tank Must

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.