Company is Great! Product arrived very promptly - No Issues there. The seal is a silicone 'plastic' formed product as per the picture. U shape to go over the glass and lip to provide the seal. The material is a bit too soft for the purpose and doesn't hold shape very well. The U is also somewhat oversize for the 3/16" glass This means that the seal does not have a firm grip on the glass and will tend to curl up at the ends in particular. Careful application of clear sealant along the bottom of the 'U" to act as an adhesive solved this for the most part. The right part but needs to be 50% stiffer and tighter across the 'U' to be perfect.