Unknown casement window crank

Thanks for reaching out to us! It appears you have an older GU operator which has been discontinued and is no longer made. Although, it is a bit hard to confirm that with certainty from the photos. 

The good new is, we do have a replacement solution that should work to help with replacing this hardware. For this project, you'll need the 39-316 casement operator; the opposite handed version is 39-315.

Take a look at the video tutorial below for a detailed explanation on this replacement.