It is a little tricky. Be sure it is seated correctly in the little groove in the w/s frame. Once properly seated in the frame, it will curve backwards slightly. When you install the w/s frame you need to press the frame inward where the rubber will then curve outward, following the curve in the w/s opening. Careful pushing it into the opening as you can crack the glass if not done uniformly all around. A little soapy water or silicone spray helps.