Window crank

Thanks for posting! Your casement operator appears to be the 39-187 Sash Dyad Crank. The opposite handed version is part 39-188. To determine if this is the correct replacement carefully compare the design and dimensions to your existing hardware. I am confident this is the replacement operator you'll need. 

This is compatible with the 39-114L Crank Handle. You may also need the 39-513 Stud Bracket.

Dimensions for 39-187