These corners with ears are for our T-2 Horizontal Sliding Windows and can be used to replace a broken one on your existing window. These corners with ear keep each window pane inside the track and allow them to slide within the frame. Note* each window pane requires 2 corners with ear. Can be shipped USPS. The website will only charge UPS due to the windows, just make a note in the order and we will refund the shipping difference.