How to notate that a list of objects is part of the same set.

Question

How do I notate that the same conditions apply to a list of mathematical objects? For example, how would I notate that both $C_1$ and $C_2$ are members of the real numbers without defining the condition on each term separately? I.e. how would I simplify: $C_1\in\mathbb{R},\quad$ $C_2\in\mathbb{R}$?