In LaTeX, \bigotimes is rendered as ⨂ {\displaystyle \bigotimes} inside math mode.
\bigotimes
⨂ i = 1 n { M i , t 1 , t 2 … t 5 } {\displaystyle \bigotimes_{i=1}^{n}\{ M_i,t_1,t_2 \ldots t_5 \}}
inside math mode.
