Cartier introduced three sizes of new Tank Must models in 2021. The Tank Must debuted in the 1970s, but we hadn’t seen any new models for years. Now it’s available again in “extra-large,” “large,” and “small” versions. The extra-large model features a self-winding 1847 MC caliber with central seconds and date, while the large and small models house both regular and photovoltaic (light-powered) quartz movements. The self-winding and regular quartz movements are veterans, but the SolarBeat is something we hadn’t seen before in Cartier’s lineup.

Cartier Tank Must SolarBeat

Cartier Tank Must SolarBeat

Right from the introduction, the photovoltaic SolarBeat models enjoyed enormous popularity. In fact, they were such hits that they became heavily sought after and hardly available while stories circulated that they would be limited models. Cartier boutiques only received a few of these watches, there were obscure waiting lists, and the prices on the gray market rose far above the then-current prices of €2,500 (small) and €2,650 (large).

beaded crown

Now, three years later, the situation is slowly normalizing. At least most of the time, we see SolarBeat models available in the Cartier online shop. However, it seems that Cartier actively considers model availability there, so some models may not always show. At the time of writing, this is true for the Tank Must SolarBeat here in the Netherlands, though it is available on Cartier’s Singaporean site.

Regardless of current regional availability, two different Tank Must SolarBeat models exist in Cartier’s current lineup, each with a choice of two strap colors. The small model has a light green or black strap, while the large model has a light blue or black strap. So, the availability situation changed over the last three years, and something else changed simultaneously — the price. The small model now lists for €3,600 and the large model for €3,800.

Tank Compared

Photovoltaic and regular quartz models

As mentioned, the extra-large Tank Must model uniquely houses a self-winding caliber. But Cartier offers the large and small Tank Must models with photovoltaic calibers (left) and regular quartz movements (right). Size-wise and aesthetically, the standard quartz models don’t differ from their photovoltaic brother and sister. And even the price is the same. The only difference is the strap material. While the standard quartz Tank Must models sport regular, grained calfskin straps, the photovoltaic models are equipped with straps made without animal materials. Except for the photovoltaic models’ occasional availability problems, I can’t think of a reason to buy a small or large Tank Must with a regular quartz movement.

Cartier Tank Must SolarBeat on wrist


I headed this article as “Hands-On,” so now that we have some historical and general information out of the way, let’s concentrate on that part. As mentioned, Cartier produces the Tank Must in three sizes — extra-large, large, and small. We no longer discuss “men’s,” “boys’,” and “ladies'” watches. But the large model I’m wearing is in the middle of the range and could have been named “mid-size” equally well. It’s always challenging to imagine the size of a rectangular watch by its dimensions on paper, but a 33.7 × 25.5mm case on my (quite regular) 18cm wrist doesn’t look “large.” Converting the feeling, I’d say it’s equivalent to a 34mm round watch.

6mm slim

Still, I think the watch isn’t too small for my wrist. It’s an elegant watch, and Cartier understands very well that an elegant watch shouldn’t be big. Together with a mere 6.6mm thickness (or slimness), the Tank Must Solarbeat has a sleek appearance on my wrist. That said, it helps if the rest of one’s outfit is somewhat aligned. When wearing casual or sporty clothing, the size of the large Tank Must might look a bit out of place. In that case, the extra-large model — unfortunately not available with SolarBeat caliber — might be better.

Cartier Tank Must SolarBeat on bracelet

Which strap to choose?

Both straps for the Tank Must SolarBeat are produced without using animal materials. Cartier indicates that a plant-based material is used to make these lovely, soft, and comfortable straps; we heard rumors about it being an apple-based material, but that hasn’t been confirmed. The large model is available with a black (WSTA0059) or baby blue (WSTA0062) strap. A black strap suits me better, so that’s what I use on my Tank Must. But mine is the black leather strap for the regular quartz model, not the plant-based version originally fitted to the SolarBeat.

Cartier Tank Must SolarBeat on bracelet pocket shot

However, observant consumers will notice that the regular quartz version is also available with a metal bracelet (WSTA0052). Unfortunately, Cartier doesn’t offer the large SolarBeat model on this bracelet, but the good news is that the WSTA0052 bracelet perfectly fits the SolarBeat model. Compared to the animal-leather strap, the stainless steel bracelet results in a €400 higher price for that model. A separate stainless steel bracelet for a SolarBeat version will set you back around €1,000, though. I think it’s worth the price because it gives the watch a more robust look, making it more suitable for different situations.



The Tank Must SolarBeat is unmistakably a Cartier, yet it’s also the entry ticket to the brand. Except for the Ronde Must de Cartier, despite its steep price increase of almost 44% over the last three years, the Tank Must Solarbeat is the least expensive watch in the brand’s catalog. And it does the job because its iconic design leaves no doubt that it is a Cartier watch. The proportions and the beaded crown set with a synthetic cabochon are elements everyone recognizes. It’s a watch that receives a lot of appreciation. Everyone seems to like it, probably due to the well-known design and the famous Cartier brand. Overall, I like the watch and enjoy wearing it a lot. Last but not least, I truly appreciate that it uses a photovoltaic SolarBeat movement. It’s a perfect fit for the unpretentious and modern Tank Must.

steel pin buckle

What do you think of Cartier Tank Must SolarBeat? Would you wear it? How do you feel that it uses a photovoltaic but, in the end, quartz movement? Please let us know your comments below.

Watch specifications

Tank Must SolarBeat
Silver-white with printed indices
Case Material
Stainless steel
Case Dimensions
33.7mm (length) × 25.5mm (diameter) × 6.6mm (thickness)
Case Back
Stainless steel
Photovoltaic (light-powered) quartz
Water Resistance
3 bar
Black, made without animal materials, steel pin buckle
Time only (hours and minutes)
2 years
Special Note(s)
Engraving of the case back is available for free