Replacement crank arm

Thanks for writing in! I am almost certain the casement operator you have is a Pella casement crank. However, it is a bit difficult to confirm exactly which one you have from the photos provided. Out of the five you've included, three of them have come in completely blank. I am only able to see the body of the operator and the end of the arm.

May I please see a clear photo of the entire operator? I'll also need to see a photo of exactly how the operator attaches to the bottom of the swinging sash.

Please let me know if you have any questions in the meantime.

Thanks for the photos. Your Pella operator appears to be the 39-175 Sash Crank Operator. The opposite handed version is part 39-176.

To determine if this is the right replacement, carefully look over the dimensions and compare them to your existing operator. 

The compatible crank handle is the 39-109B 3/8" Handle for Pella.

Dimensions for 39-175

View of the arm of the 39-175 window operator.