What is the unit of molar density?

I'm reading *Unit operations of Chemical Engineering*, 5th edition by Warren McCabe.


They defined the "molar density $\rho\_{M}$" as $\ce{\rho\_{M}=\frac{n}{V}}$. The parameters $n$ and $V$ are the number of moles and volume as usual (they are indicated in the summary table of all the symbols at the end of the chapter). To my understanding, $\rho\_{M}$ indicates how many moles of a molecule are there in a volume unit and its unit should be something like $\ce{mol/m^3}$ or $\ce{mol/cm^3}$.
[![The definition of <span class=](https://i.stack.imgur.com/rklY4.png)$\rho\_{M}$" />](https://i.stack.imgur.com/rklY4.png)


However, the unit of $\rho\_{M}$ in that table is $\ce{kg\cdot mol/m^3}$. Why is there the presence of mass?
[![The symbols with explanation at the end of the chapter](https://i.stack.imgur.com/uNep4.png)](https://i.stack.imgur.com/uNep4.png)


