Universal window double arm operator

There is no such thing as a universal operator, unfortunately. Each part has to be replaced with something specific. In your case, it looks like you have either our 39-253LB or 39-438B. The only difference between these two products is the style of the slider at the end of the arm, which is not visible in your photos. The video below will explain what I mean.

Regardless of which one you go with, you'll also need a new 39-451 cover.