Need Alenco replacement double pain window clip

This part is known as a top sash guide. We carry a ton of them, but I'm not sure exactly what yours is. The best match depends entirely on dimensions, which are very specific for this kind of part.

I would start by looking at our 18-166. This is a possible option, but I highly recommend reviewing the dimensions we show to confirm whether or not they match. If they differ in any way, please tell us exactly how.