There are many different operators, for example sums
$$\sum_{i=1}^\infty$$
or products
$$\prod_{i=1}^\infty$$
But what does this operator stand for? What does it mean?
$$\mathop{\LARGE\mathrm K}_{i=1}^\infty$$
I am sorry for this might being a dumb question, but I tried googling things like "big K operator math" and didn't found anything.
