  This paper focuses on a generalization of the *-product called
$\mathbf{C}$-product. This product, first introduced by Durante, Klement and
Quesada-Molina, was used to characterize classes of compatible copulas. The
$\mathbf{C}$-product of copulas $A$ and $B$ is defined to be an integral of a
function which involves the copulas $A$ and $B$ and the family of copulas
$\mathbf{C}$. However, measurability of the integrand in the definition is
questionable. We will discuss this in details and attempt to re-define the
product. Then we derive some properties of the re-defined product.
