I believe you either have our S380-27 or S385-27. The difference is the bottom shoe; the S380-27 comes with our 15-005, while the S385-27 comes with our 15-004. You will need to carefully compare our measurements to yours to confirm the better match.
A contractor says:
May 12, 2016
Thank you for your reponse, since we have a lot of windows I would have to remove them and count them and measure the weight of the windows and the height so I could find the right one.