Those windows is Marvin brand parts numbers is 30744A. I need left and right 2 parts.

Thanks for reaching out! Your casement operator appears to be an older version of the 39-013 and 39-014 Casement Window Operators. The box style base on your operator is no longer available but I am confident these should work as a replacement, so long as the dimensions are a match.

Be sure to take a look over the other hardware and accessories tagged below.

Dimensions for 39-013

Additional information for 39-013