What are the elements of the group $6 \mathbb Z$

Question

I know that the group $\mathbb Z = \left\{ ..., -2,-1,0,1,2,... \right\}$, but what does the group $6 \mathbb Z$ represent? I was thinking it might be $6 \mathbb Z = \left\{ \dots, -12, -6, 0, 6, 12,\dots\right\}$ but I am not familiar with this denotation.