Looking for an Anderson f-9400-8 b window operator

I notice the slider is missing at the end of the arm of your operator, but I think our 39-332 would make a fine match. Look it over and see what you think. 

See our 39-099 Andersen Awning Operator, which has a 9" long straight-arm. Compare and see if you think this is what you need. Now, you'll note the base of the 39-099 has a hole spacing of 3-11/16". With some older versions of this operator, the hole spacing is 2-11/16" instead. In that case you'd absolutely need the 39-362 adapter. To be honest, I would advise getting it anyway just to be safe; if it turns out you don't need it, you can return it via our Return Policy here.