What do Cartier's watch sizes "SM", "MM", and "LM" mean?

"SM", "MM", and "LM" are abbreviations for the sizes of watch series made by Cartier, a French luxury jewelry brand.

"SM" stands for "Small Model" and refers to a small watch with a diameter of about 28 mm. "MM" stands for "Mid-Size Model" and refers to a medium-sized watch with a diameter of about 31 mm. "LM" stands for "Large Model" and refers to a large watch with a diameter of about 34 mm.

These abbreviations are used to easily identify the sizes of Cartier watch series, and also to convey more accurate information about the different sizes of the same model.