Operator

Thanks for writing in! There is a chance that your casement operator could be either our 39-253RB (and its opposite handed version 39-253LB) or our 39-439B (and its opposite handed version 39-438B. To determine which of these is the correct replacement, you'll need to compare the design of the operator. 

The attachment at the end of the straight arm will help to determine which of these is the correct replacement. Take a look at the video below for a detailed description of the differences and how to determine which of these is the right fit for your window.